Obviously some countries are way too small to produce so many artists and bands like the USA. However Iceland, for such a small country, it is managed to give us the beloved Bjork, who is probably (in retrospect) the most important female artist of the 90's as well as the most popular Post-Rock band Sigur Ros. Love them or hate them but Sigur Ros comes to most people's mind when talking about Post-Rock or 00's Alternative music. Even American's Simpsons gave them an appearance (not Mogwai or Talk Talk)
Mostly I think the discussion boils down to the government and cultural perception of a nation in the world. When people think of Romania they usually only think about Ligeti. Why is that? It's because American director Stanley Kubrick decided to use his music in one of his films. Had Kubrick not done that most Classical "connoisseur" would dismiss Ligeti as a some Romanian gypsy trying to play Western man music. But, the American man gave a seal of approval and now he is known and beloved.
The government didn't do much to help out, constant censorship and bad creative environments doesn't kill the music, but it kills the music's prospect of breaking out to other nations.
Phoenix (great Romanian Prog band) and Rodion G.A. (weird group that played completely their own style and practically created Minimal Synth) would have become staples of their respected genres had they only been doing their music in a different nation, where an artist can prosper (like the UK). The rest of the world doesn't care about the music of this nation, the government isn't helping. The chances of this music breaking out into the ignorant American's stereo is quite low.
Ok I am done with my autistic post.