ck... I agree with you that players from the U-20's team tend to only give out a small number of players to the major teams (unless you are argentina, where Messi, Tevez, D'Alessandro, Aimar, Riquelme, Gago, Mascherano, Cambiasso where all members of different U-20 teams that won the WC). But the difference to other teams that have been going on in the history of the Mexican team, is that now we are exporting players while before we werent.
I mean right now Pardo and Osorio just won a championship in the Bundesliga, Salcido did the same in Eredivisie with PSV, Rafa had a down year with a lot of injuries, but he is still with Barca, as is Gio, and Vela is in Arsenal. That is not to count that there is a kid playing in Slovakian football, and Cardozo is in Olimpiakos, and Guardado is getting interest, Ochoa too, Bravo was going to go too, there is a kid in Chile, there is another one in spanish soccer (though I doubt he is going to want to play with us since he is a spanish national too).
You know as well as I do that the only way to get better in this game is if the best players on your team are moving to play in Europe, that had never happened in the history of the Mexican game, and it is really happening now. So if you where to ask me what is the difference between that established mexican record and now, it is that we are in Europe, we are doing well in Europe, and more of us will be going to Europe.