Could you please stop posting uncivil and/or unsubstantive comments to Hacker News? You've done it repeatedly, it's not what this site is for, and we eventually ban accounts that do that.

It would be great if you would review https://news.ycombinator.com/newsguidelines.html and take the spirit of this site to heart when posting here.

But isn't it a platform for all ages? In which case, it would be illegal for YouTube to host porn, wouldn't it?

Age control isn't a legal requirement for websites that host porn in the USA as far as I know. Google, for example, will return porn in image search results (if you disable the safe search filter), and you don't have to verify your age first to do that.