"Why Silvally is an evolution and not a form change"

I apologize if someone's already talked about this.So I've heard a bunch of people complain that Silvally being an evolution makes no sense because all that happens is that the helmet gets removed, and that it would make more sense for it to be a form change. While I can see where people are coming from, I'm fairly certain the reason it's an evolution is for the sake of it being permanent. The idea is for Type: Null and its trainer to be able to trust each other enough for the helmet to come off, as a sort of character/relationship development rather than something that can be switched back and forth.Besides, are we really going to act like taking a helmet off is too insignificant to prompt an evolution when we have Pokemon that are 3 of their pre-evolution stuck together? via /r/pokemon http://ift.tt/2iXXr35