I suppose an argument can be made that Batman was a big factor in less "macho" actors...but even before Batman you had guys like Tom Cruise (Top Gun, Legend) tipping his toe in the action/adventure genre and making producers think that younger pretty boys could sell tickets to action movies. And, of course, Harrison Ford was never a real gym rat but he was still starring in the Indy films, the Jack Ryan films, etc.
And, as for special effects, I think Sly's absolving his pal Arnie (and James Cameron) of a lot of responsibility there. Between the Terminator films and True Lies I think they did more than anyone to make action films a special effects driven genre.
