Ask HN: Why don't more startups adopt Flextime work schedules?

Why don't you think they do? Are you asking about any particular company, market, or region of the world?

I'd guess most startups already have flextime. You can come in real early or stay real late, but either way, you're going to work more than just 9 to 5. Getting things started is hard. Keeping a bigger business rolling along is easier.