RR
I think that if the US develops a significant talent base as it is progressing at the moment, then everyone will be happy. I think that objections would start to be raised only if the MLS started to introduce different rules to the FIFA norm or whatever, which I understand they are consciously trying to avoid this time.
Part of the issue, I think is that the availability of world soccer to the US gives an instant comparator with your domestic game which only modern technology has been able to provide - and this is a two-edged sword. For while you are able to catch top-class soccer from various leagues on TV/cable quite easily, the quality of your domestic product is, to be honest, so far removed from that such that people who have become enthused by watching the EPL on TV must get completely underwhelmed by going to an MLS game. Having now been exposed to some of these games in full, I can comfortably say that the MLS is, at best, League Division 2 standard (ie the 3rd tier of the English domestic game - home to Simo's beloved Hartlepool..).
So whereas in the past fans would grow to enjoy the domestic game and then begin to chance their arm on the world stage, now prospective fans are already being exposed to the finest that the world has to offer (and Man City) - against which the MLS is naturally not going to look great at the moment, because it is only just developing.
Having typed all that, you can take heart, because last time I looked, you were above us in the FIFA world rankings.

"The players come from all over the world, the money from deep underneath the Persian Gulf, but, as another, older City poster campaign put it, this is their city. They may now exist in the global spotlight, but they intend to keep it that way."