It's a pretty good barometer for success - 99% of founders don't get to that point.
Who knows? Why do you think only people who have gotten to $15K MRR can offer value?
I agree it's something of a signal, but I'd personally consider that a very weak signal. shrug
In that case, we fundamentally disagree, and this discussion is fruitless.
There's also the problem that you don't know the value of the hypothetical "person who hasn't gotten to $15K MRR" yet. If they started their company 2 weeks ago, they probably have an MRR of $0. Does that mean that they have nothing of value to tell you? That depends on a lot of other variables.
Anyway, you're probably right... we probably just have fundamentally differing world-views. I lean towards the "you can learn something for everybody" mindset, and try to late-bind judgment on people's value as advisers until the last possible moment.
But that's just the thing... nobody actually knows if that level of vetting is meaningful... it may perform no better than chance in terms of identifying "good" startups (however you define that). This experiment will actually be very interesting exactly in that it will help YC see if their vetting IS as good as they think it is.
please build a mastermind group that requires an MRR of at least $15k. I'd pay good money to be a part of that
Sure, having a $15K MRR shows something about a company, but why do you think that is the best criteria to identify founders/companies to network with?