I have no idea. Most lads I know (and we're in our 40s and 50s) really couldn't give a shite about what consenting adults get up to in their own bedroom, and I'd hazard a guess most people younger than us are even less bothered than we are. So I don't really know why gay footballers don't feel comfortable coming out.
I reckon there would be quite a lot of positivity, with fans policing themselves much in the way racists are shouted down by the majority, so would the homophobes.