Rotom forms are only part of the problem, but I just don't trust anyone who uses legal hacks. If people don't take the time to RNG or at least EV train their pokemon the correct way, then what's to stop them from inputting illegal EVs, IV combos, movesets, etc.? People with legal hacks have the option of creating pokemon they desire such as a flawless WishBliss, a flawless Linoone with Extremespeed and Bellydrum, or other flawless pokemon that are hard to come by legitimately.