If it's all about execution and not the idea, why does YC have stealth-mode startups, like this music startup that's hiring?<p>http://news.ycombinator.com/item?id=2043422
Announcing that you've been backed by YC (or any investors) can be enough of a news story to generate some good press, which is most useful if you can control the timing to coincide with other interesting things that you've done (like big feature deployments, major partnership, traction announcement) or want to do (like raise money or get the PR ball rolling).<p>By naming themselves now, they'd be throwing away future exposure without receiving any immediate benefit.<p>I don't know what phase the mystery startup is at, but while you're very early stage it's also often desirable to enter investors' radar with a bang when you're ready to raise money, and not before, since novelty & freshness can help offset the lack of evidence young companies are defined by.
The "it's not about the idea" idea refers to people with no technical background who think they can get rich simply by having an idea, like say, "a site where people can upload and watch videos".