As a non-American who applied to YC twice the article was a pleasant surprise. However I'm not sure America is as attractive to non-American founders as some people think. I'll explain (my arguments are mostly personal perceptions...I have no practical evidence yet on any of this since my own startup is still at the "wrote some code" stage).
Let's suppose there are 2 types of founders: people who have enough money & connections, and the young "live on Ramen noodles" type founders.
For the "money & connections" type, a lot of foreign countries offer cheap but still qualified programmers and don't put too many obstacles on founding companies so if your country is like that it might make sense to stay. For the "Ramen" type, many of them may not afford America's often high living costs.
As for the argument that the US provides a better/more free market... even this is changing: The internet probably allows relatively easy selling to worldwide customers from any country.
All that said, the American dream probably still lives on and many people would likely provide counter-examples to my limited point of view. Of course pg didn't claim that coming to the US is a no-brainer for every single talented hacker. There are probably enough of those who are interested to satisfy the 10,000 founder/year goal.
"For the "Ramen" type, many of them may not afford America's often high living costs."
I think the algorithm PG proposes is something like this:
1. Produce enough that you would be able to convince someone to fund you. Maybe this takes a prototype, a convincing sales pitch, ramen profitability, etc.
2. Convince someone to [seed] fund you.
3. Move to a place with an environment favorable to startups.
4. Continue working on your product, now with access to investors, other founders, good employees, great weather, ...
The idea is to get to step 4 as fast as possible. In most parts of the world you'd never be able to find good investors or a startup-supporting culture, and that counts for lot. As PG has pointed out, there's a huge variance in startup-friendliness even amongst the major cities in the US.
Let's suppose there are 2 types of founders: people who have enough money & connections, and the young "live on Ramen noodles" type founders.
For the "money & connections" type, a lot of foreign countries offer cheap but still qualified programmers and don't put too many obstacles on founding companies so if your country is like that it might make sense to stay. For the "Ramen" type, many of them may not afford America's often high living costs.
As for the argument that the US provides a better/more free market... even this is changing: The internet probably allows relatively easy selling to worldwide customers from any country.
All that said, the American dream probably still lives on and many people would likely provide counter-examples to my limited point of view. Of course pg didn't claim that coming to the US is a no-brainer for every single talented hacker. There are probably enough of those who are interested to satisfy the 10,000 founder/year goal.