I think the "go and win the World Cup if you want to talk" argument has been engineered to make players who already come from powerful football nations appear more important than they are. Like you'd have to be born in Spain or Germany to be a really, really top class player.
If Yaya Touré's skin were any thinner they'd have to carry him around in a bucket, but he's not wrong when he claims that he's been somewhat overlooked because of his nationality. I think it's for the same reason that people very rarely count George Weah in the company of Romario and Baggio and those guys, even though he and Ronaldo (the real one) were the two players that completely rewrote the rules for how a striker was supposed to play.
Of course in Weah's days the tv cover was also a lot worse. People usually didn't know much about players in other leagues. And it wasn't like Liberia were going to do anything in the one big tournament everybody in the world had access to, which was the World Cup.
