I remember PONG and everything after that, I don't think its the games so much as the gamers.
Cussing.
Religeon.
Sexual situations.
Among others.
Any of these are hot button issues for some gamers.
Game companies typically take the path of least resistance and that leaves us here.
Also in those days us gamers were far and few in between,to few people to get worked up by Larry's exploits. Now days games are mainstream ,they cater to millions instead of thousands and as such have to cater to mainstream views of the world in which they are created.