I agree, there's no reason to use a gun that's still stronger than most of the guns before it and also has homing rockets.
Oh, wait.
You don't think buffing it from 63 to 70 damage because it was underperforming, and then immediately smacking it down from 70 to 50 damage (A whopping 29% nerf) the very next patch is completely schizophrenic, nonsensical balancing?
Ranged is already mediocre DPS-wise (and just feels terrible clearing end-game content on Expert, and this is coming from someone who has cleared all of Expert solo without any cheese and was always a huge fan of ranged), and is in an terrible place as far as weapon variety is concerned; and this ridiculous change further reinforces that only viable option left for Ranged players is the SDMG which is yet another comically lazy Megashark clone, while Melee, Mages and Summoners have never had more variety in their viable options.
2. Vortex Beater and Phantasm were NOT receiving Ranged Damage benefits, including Stealth, before 1.3.0.5. So if you are sitting there in Vortex Armor and Stealthed, your Vortex Beater/Phantasm was displaying an increased base damage, but it wasn't actually dealing it. Lets say your Vortex Armor, Stealth, and Ranger Emblem and Sniper Scope add some . . . I dunno, 100% extra damage. VB and Phantasm WERE NOT getting these in practice. This was added back in, and it ended up literally doubling (or more) both of their DPSs in combat . . . so when you see things like "Vortex Beater lost 20 damage without compensation" this isn't quite accurate. You may have lost a chunk of listed damage on the tooltip, but the actual performance of the gun has improved.
It was severely nerfed for those who were using it without Ranged armor. Twist it all you like, but that's a hard fact.