You know in 20+ years of founding and working at a bunch of different startups and companies ranging from big companies in fly-over country, to team-of-2 bootstrapped 6-figure businesses, and all the way up to super hot pre-IPO unicorns; one thing I've learned is that great people that you gel with and might want to start a company with are everywhere in equal proportions.

Sure, there are probably slightly more of them in Silicon Valley, but also SV is full of wannabes who are playing house, so the signal to noise ratio is actually less. I feel any kind co-founder dating suffers from the exact same thing. YC's name gives it more legitimacy, but that very fact attracts more dedicated wannabes who are just playing house harder.

Ultimately after all these years I keep coming back to Joel Spolsky's idea of working with people who are "smart and get things done". That's it. I am skeptical I will find someone I want to work with on a co-founder dating site, because the people I want to work with are too busy trying to do a thing with the resources available to them versus looking for a longshot silver bullet. There are exceptions of course, but this is just my gut instinct, you might take it with a grain of salt since I waste a lot of time commenting on HN :)