I tried very politely to explain this problem to Coinbase about two years ago during an interview, and their reaction was to ask about my college degree, give me a bunch of weird whiteboard problems that had nothing to do with actual programming, and then show me the door, one day after I helped fix all of their client libraries when they switched SSL CA providers and didn't even realize it, and then provided a pull request to coinbase-ruby providing concurrency support using this very same threading mechanism, on the two-hour flight there (proof: https://github.com/coinbase/coinbase-ruby/pull/6).
Are you being fair to Coinbase? There are two sides to every story.
But if this is true at face value, then it's disappointing to hear that a YC startup would care at all about a degree or about whiteboard problems, of all things.
If a company cares about what a programming candidate can do, then caring about a degree or whiteboard problems is caring about the wrong thing. Thought experiment: How much better or worse would YC's results be if they had candidates solve whiteboard problems during the interview? (Admittedly, YC cares about degrees though.)