I'm gonna have to disagree with this point. Most of the Pokemon that get Pure Power/Huge Power need it to have any form of value when battling against other people. For instance, Azumarill without Huge Power has an attack stat of 75. Azumarill needs Huge Power to do any damage, and if it got nerfed Azumarill suddenly goes from a bulky yet hard hitting Pokemon to just another wall that does worse than other walls. The -ilate abilities are unique, and allow you to use moves you normally wouldn't. That Protean nerf doesn't make sense. If your gonna nerf one type changing move, nerf them both. If you halved the power of any Flying type move with Gale Wings, then suddenly it's worthless. You might aswell use an actual priority move, since every attack you do, regardless if you needed the priority, is suddenly half as strong.
These random nerfs won't fix anything, they'd just screw a couple of Pokemon over.
The problem here is that Huge/Pure Power is
solely why Azumarill is OU material and why all it's other abilities and Special Moves are useless. Azumarill has a Base 50 Attack stat normally. Huge Power gives it a whopping
Base 150 Attack stat. That's right, it gives Azumarill an artifical 100 BST boost and the ability to singlehandedly carry trainers through the main game for the most part. Furthermore, the sheer OPness of the same ability is why Mega Mawile got banned by Smogon and Mega Medicham is such a huge threat. If Huge/Pure Power is to be nerfed; the pokemon who relied on the ability (Azumarill line, Medicham line) will need buffs to their attack stats, as both lines lack in BST (Azumarill has 420 and Medicham has 410 before Mega, around 100 BST below most fully evolved pokemon)
because of Huge Power.
The -ilate abilities let you use moves you normally wouldn't because the user usually gets STAB out of it, before the stupid Power increase. Quick Attack and Double Edge would still be useful on Mega Pinsir without the boost while Hyper Voice would be still useful on Mega Gardevoir and Sylveon in Doubles because it hits multiple Pokemon as opposed to Moonblast hitting one. In their current state, with the 1.3x boost, they have broken far more pokemon than what they have balanced. It made Mega Salamence become so broken that Smogon had to ban it from
Doubles on addition to Singles and IIRC Mega Gardevoir got banned because it's Hyper Voice made it too powerful. Others that didn't become broken, it either will be their only viable ability (in the case of Sylveon) or it is the main reason it is threatening (eg. Mega Pinsir). Nerfing those abilities will probably make Mega Salamence manageable, Mega Gardevoir and Pinsir being in line with most of OU and give Sylveon more of a reason to use other abilities. If those abilities were to get the nerfbat, I would add in more Special Normal moves so Specially-based users have more reason to use their -ilate ability, give Sylveon another good ability.
Protean is the only reason why Greninja became as OP as it became, especially when OR/AS came out when it had access to Gunk Shot so it can screw over the fairies that walled it, as Greninja would be bottom-tier material without the ability. My suggested nerf will nerf Greninja so it will become a managable threat and not an OP monster while the other pokemon that gets the ability, Keckleon, will remain untouched for the most part (Since when are you going to be using Keckleon in an offensive role?). By the way, what other type-changing abilities are there? Colour Change and Multitype are the only ones I know of; Colour Change happening after you take the attack and Multitype changing type depending on what plate Arceus is holding.
Gale Wings, on a fundamental level, is broken and is the sole reason why Talonflame is so powerful in OU (IIRC, it even got banned over it). Like Shadow Tag (which I, by the way, also want to see nerfed so Mega Gengar and Gothitelle wouldn't be so OP), the ability Gale Wings grants is nigh impossible to nerf without making it useless. The best way I thought I could go about it is by halving the power of Flying-type moves, as it still gives Talonflame (and potential future Pokemon that has it) the ability to revenge-kill just about anything that has low HP without giving it a Choice Scarf, while making it balanced and gives reason for the user to use it's other abilities.
Pokemon has always been designed to be a competitive game. That's part of what many people play Pokemon for: to catch and train their team to beat their friends/other people's teams. Gen 2 didn't have to introduce Steel/Dark type to balance Psychic, or have held items, or split the Special stat. Gen 3 didn't have to introduce double battles, or abilities. Gen 4 could've not introduced the physical/special split. Gen 5 could've just not introduced Hidden Abilities. Gen 6 didn't need the Fairy type.
Pokemon has always been a game for multiplayer interaction, and the metagame has been constantly evolving with each new generation.
Sure, if that's how you played the game. But it is a fact that Pokemon was
never designed to have a metagame in the first place but rather the metagaming aspect really took off with Pokemon Platinum, or else we would have been seeing more balance on Gamefreak's part early on.
Gen I's metagame was a complete and utter trainwreck. Your only options were offense and you had to be fast; with Alakazam taking the cake because not only did it hit ridiculously hard with it's unresisted STAB but because it was so fast it crit at an insane rate. Gen II fixed a lot of issues, but there came problems like the Female Attack IV issue and several types still had a huge lack of representatives and moves (IIRC Bug, Dragon and Steel each had like 3 moves all up). Beyond that I can't comment.
Then we get to Gen III, with all of its new additions and whatnot was IIRC when the competitive scene started becoming noticeable. Gamefreak started catering to them with Gen IV, by adding in numerous features like the EV boosting equipment and the Choice items in the postgame, and that's when competitive really took off. Gen V was when Gamefreak started catering to the metagame at large, but it still felt like something to do on the side after you beaten the games. Finally with X/Y, Gamefreak made it so easy to just force your way through the main story so you can get to playing in the metagame ASAP; where it felt that the point of the game was largely to get you out of the main story ASAP and play the metagame and the main story suffered from it.
I am not saying to throw out the metagame, but I rather I am saying that I want to see a good singleplayer main game experience and think of playing competitive as a side thing instead of said metagame being the main attraction. I don't want Pokemon going the way of many online shooters that you play only for multiplayer.
Edit: The innovations that you mentioned that the later gens did that you listed, except for the Fairy type and arguably Hidden Abilities, were
not made with competitive in mind; but rather with ingame flavour and/or balance. The Psychic nerf in Gen II was needed because Psychic was
obscenely overpowered even for ingame while the Special stat did not make much sense being dual Attack/Defense and held items allowed for far much more flavour and depth in the games. Double Battles were introduced to make battles more than just 1v1 and Abilties were added in to add flavour to pokemon. The Physical/Special Split was introduced because the attack category designation based on types was simply was not going to cut it with the ever expanding variety of pokemon (case in point: Weavile would be
useless if the split did not occur; as both it's STABs would have been Special then) and it simply does not make sense to have things like Fire Punch run off Special Attack and Hyper Beam run off Physical Attack.
