I think
men are not encouraged to show enthusiasm about women in non-predatory ways
A) straight men following a bunch of female celebs comes off as creepy
B) they’re not “allowed” emotional fantasies as much as women are (I’ll expand on this...) https://twitter.com/delia_cai/status/1362075371651407877

Internet Boyfriend-ness is about physical attraction, of course, but there’s also the emotional fantasy of it. Peter Kavinsky opens himself up to learning about LJ. The Duke of Hastings sees Daphne as a friend and is protective....

Men are not often given room to have emotional fantasies about women beyond “doesn’t nag.” Ultimate male fantasy = beauty, sexiness, ability to make other men jealous of you.

When I try to think of Internet Girlfriend examples, per a straight male POV, I see maybe ScarJo, someone whose best known characters in recent years have a lot of physicality and few emotional displays (alien, A.I., cyborg, spy).

Oscar Isaac was labeled Internet Boyfriend, and hardly anyone could name a movie he was in. He was just a bunch of gifs. He was physically hot but also his eye contact... as in he *saw* you. Men aren’t really encouraged to say they need someone who *sees* them (but they should).