It is as you say actually impossible to tell if these kinds of opinions are being posted for trolling purposes or by someone dead serious. The way I see it its enough that some people actually believe their vacuous arguments about how terribly sexist art is. Since not all of them are trying to be clowns, and they sometimes actually manage to garner some influence or change that means someone needs to point out and counter their bullshit. Sometimes a troll might get what they want, but I think its better to counter one more SJW nonsense thread isntead of starting an investigation to try to separate fake insane persons from actually insane people. ^^
