Huge concentration of talented people here - why don't we have a marketplace yet? There's already a jobs section, but we could have freelance projects, etc.
Because maybe... and this is a stretch so bare with me, not every internet property needs to be endlessly commercialized so a handful of individuals can buy vacation homes in Lake Tahoe.
It is an acquisition funnel strategy for YC. Their main source of income comes from YC startups. This platform is just to attract those startups/founders.
The jobs section you mentioned, that is only for YC startups.
No thanks. HN is uniquely not-commercially-focused, and I think most readers would like to keep it that way.