The site you are commenting on is effectively an Ad for yc. Should that be banned?
There are many categories of products that are already not allowed to advertised, where meta-discussion about the products still works fine.
Such a weak minded assertion as "ban all advertising" without considering how that impacts freedom of speech is unbelievable.
Banning all color in ads, all images/videos in ads, all ads in public (busses, billboards, etc), music in ads. Simply black and white text information (which is what YC adheres to).
Any step in that direction I support.