This argument irritates me to no end. I ship Matt/Foggy because I enjoy friends to lovers and I enjoy pairings that have a character or characters that I can interpret as mentally ill and like.......a whole host of other things. There is migratory slash fandom for sure but I don't think you're finding much of it in Daredevil - Matt/Foggy in comparison to juggernaut slash ships is tiny and is more likely to just be people liking gay friends to lovers than it is people seeking out a pairing to read ten thousand gay fics for, doesn't matter for who or what.