This. It's more about avoiding bad PR. And it doesn't have to be porn. It could be guns, vaping, violent movies, gambling, whatever.
If you're selling baby shampoo the last thing you need is some parent posting on Twitter about "Why is this baby shampoo brand advertising on a sight that promote horror movies about human centipedes?"
If you're selling baby shampoo the last thing you need is some parent posting on Twitter about "Why is this baby shampoo brand advertising on a sight that promote horror movies about human centipedes?"