I never got why, please explain.
Because it was shit. You'd think it was shit too but because fallout 4 was released you now want to look back glowingly at 3 and pretend it was actually really good and shit all over the newest one.
Because you're a faggot. And because you're underaged
Its just /v/ contrarianism. The original Fallouts like Morrowind had great story and writing but terrible gameplay. But since Fallout 3 made the series into one you actually would play contrarians hate it.