I agree with the poster that shelling out $1500 for a 10 minute interview, and then basing a significant investment decision on that interview, does seem curious - but, as the poster said, they see hundreds of teams, and have done for a number of years now, so you'd think they would know almost instantly what they're looking for.

I've done a lot of technical interviews myself over the years, and, assuming I'm not pairing with a fellow interviewer who wants to spend 20 minutes outlining the history of the company and describing the role before actually asking any questions, I can usually tell within five minutes, and after really only a couple of carefully chosen questions pertinent to the problem domain, whether the person is likely to be someone I'd want to hire. (And, just like YC, I get it wrong sometimes. That's life.)

The tone of this piece sort of read to me as "I want to make it clear that I'm not complaining about the process, but I'm going to complain now anyway" - it seems like their observations were quite fair, adding a space to your product's name hardly seems important, and they were courteous and did actually give you feedback, which is probably more than you can hope for from many companies.