But...
I would argue that AI research (depending on how you define that. AI is a BIG field) is more demanding that "flavour of the month smartphone app" development. And in the past, I scoffed when I heard people say things like "70% of so-called developers can't complete FizzBuzz." Then I started interviewing a lot of candidates for developer roles at the $dayjob and whaddaya know... it seems that most of the candidates we get can't successfully code FizzBuzz. And that's a pretty low bar.
So I dunno... part of me believes there are plenty of people who could contribute to AI research, but part of me is shocked by how few people can even write the most trivial computer program.
Are there fewer than 10k people with a master's in the subject in the entire world?
I don't think having a Masters has much to do with anything. We get folks all the time with a Masters in C.S., even from relatively prestigious schools, and they can't even code up FizzBuzz.
Anyway, I wish I had a better answer for you, but recent experiences have me questioning just how many really competent people there are out there.