It was Bendis, a Marvel darling at the time.
Yeah, I still laugh at the language used. "Full Gay" which makes me cringe because then there must be a partial gay or quarter gay or any other measurement one wants to use. I suppose it supports Jean's everyone is bi concept.
I don't like it in fanfic either, I don't get why there needs to be a qualifier for sexuality.
I've read things like, "extremely" gay, not sure what that means but whatever. Or "not just gay, but really gay," again, whatever. I don't think qualifier words are needed.
Certainly nobody applies qualifiers for straight or with the word hetero. Apply a qualifier for those words and its equally absurd.