Honestly, there is no good excuse why we can't just pick our modifiers by now. Terraria is not an MMO, no matter what people seem to think. The idea of grinding in a game like this is plain silly. I would even go so far as to invoke a Minecraft comparison. In Minecraft you can enchant books with the bonuses you want. So why can't Terraria? (To say Minecraft does ___ better than Terraria is taken as an insult by many, and doing so should prove the silliness of the reforge system.)
My point, we are in 1.3 now. There are ways to farm unlimited money while being afk. (And afk farming isn't gameplay, it is an exploit to deal with a broken feature.) The reforge system is needlessly punishing to players who don't play all day. Especially when you consider that most weapons become obsolete in roughly an hour after obtaining. (Assuming you are moving forward with the game and not farming.) Nothing is a bigger slap in the face than finally getting the materials or drop for a weapon and have it come up Broken.
I will second that a warning should come up before reforging any max tier item (including menacing, lucky, warding, etc.) But, I wish to add a +1 and say that even if it is locked until after Moon Lord, players need to be given the ability to select the reforge of their choice with a proportional price tag.