Alex is here because after being rejected by his peers, his love and just about everybody he ever met, he has to convince himself that all those people he once esteemed are now beyond contempt.
The easy way to get the reassurance fix needed for that is to go to websites populated by people he does consider beyond contempt and be as obnoxious as he can, so he can put some bitter-sweet vindication balm on his real life scars.
I pity him.