The porn industry has always been outcast, banished from the rest of good-thinking society. Because of that, they aren't held to the same standard of inclusivity or bother to be family friendly. Hence why porn can afford to be more genuine than other companies : they have nothing to hide and boldness is actually good for their image.

Pornhub just follows that legacy and has a very smart marketing strategy on top of that.

It'd be funny if Pornhub buys tumblr and porn started to run rampant on the site, driving out all the SFW people.