The issue with Franco is not just one or two rumors. If you were to spend some time on the Hollywood rumor sites you would see that there are a lot of stories from different people about different incidents.
The consensus is that not only is he a predator, he is pretty much a jerk. I think the fact that he treats everyone like crap makes him more unliked than the sex stuff.
This stuff has been going on in Hollywood ever since they invented celluloid...............