Player development is like a flop of texas hold 'em... it's easy to look at the flop see what could happen and maybe you can even compute the odds, but you can't be certain how it'll end up at the end.
I think you might be onto something about how the MLS lacks the emphasis on possession and individual ball skills, but to make an argument that the MLS is treading on the success of Sam's Army is a stretch. The opportunity to play professionally has expanded the number of players who have the opportunity to develop. Even Portugal's golden generation of stars couldn't deliver in the big tournaments--they had to wait for the second generation.