I'm sure this has been suggested many times before as it makes -10 sense to have a feat that can be rescinded at any time not be passive. And once a new class comes out, how are they gonna let people pick a new feat where they once had completionist? Are they going to have to go to Fred and pay for it?
Lithic, I'm curious, have you ever not taken the feat on a character you've leveled? That would be pretty sad.
But anyway, that's a side discussion that's been hashed to bits.