Lot of interesting questions on the Group G thread about the future of soccer in the US. Only some of them getting answered.
Soccer is basically a regional sport in terms of national team player development, and to some extent fan interest (though less so lately it appears). Northeast, Florida, Texas, Pacific, (and Europe, half a dozen or so MNT players were effectively developed there) covers the strong majority of USMNT hometowns. This is similar to hockey in the north and northeast, only soccer's strongholds are more fortunately located from a demographic perspective.
Despite this, soccer is still less popular than hockey (similar per game attendance thanks largely to Seattle, but in many less home dates). So how does that change?
For this I look back to the NBA in the 70s. It was largely looked down upon as inferior to college ball, and rose hand-in-hand with the rise of hip-hop culture in the US starting in the 80s. It could be argued that the racial makeups of the Celtics vs. Lakers played a particular role in drawing attention given what was happening in the culture at large. As hiphop culture became more accepted and mainstream, the NBA also grew in popularity.
Soccer is positioned to benefit from the likely next broad cultural shift, in concert with the increase in both number and 2nd/3rd/4th generation (and more) ethnic Latinos that are US citizens. If the concussion issue in the NFL continues to mushroom, that will play in as well (unless soccer ends up being caught up in it as well).
So going back to "what comes before" the rise of soccer, it's more viewership both of European and domestic games that will drive the money to the domestic league to bring in better talent and interest young players in taking the game seriously rather than playing it as a kid and then deciding to specialize somewhere else. The money is there worldwide, but kids here haven't been seeing it because, and this may comes as a real shock, most Americans don't really care much about what's happening outside the US. That's changing though and will continue to do so.
America's advantages are obviously population, a reasonably well-off lower class (compared to many soccer playing areas, even most poor can afford to play in a city youth league and won't be shut out of opportunities), an established market for sports entertainment, and a tradition of excellence in many other areas of athletics. There's an expectation to be good on a national level. And over African countries that have the same issue of having great athletes but struggling to develop great national teams, the US can more easily build out a support infrastructure if/when it becomes necessary. We can build facilities, we can pay good coaches.
As far as the "well Lebron James could have been a soccer star" argument...yeah probably not, but that doesn't change the need for the talent pool for soccer to increase and to include more athletes that could have chosen to be, say, a running back on a football team or a point guard in basketball. Imagine if guys like Darren Sproles or CJ Spiller had soccer balls in their cribs? Given enough of them, development would be inevitable.
The outer limits for height right now in soccer for non-goalkeepers appears to be in the 6-4 range for the best tall defenders and strikers with a few exceptions among central defenders. But Yaya Toure, Edin Dzeko, Zlatan Ibrahimovic, Lukaku, and a few others are 6-3/6-4 and quality players. For players tasked with much more ball advancement, ball control or ball distribution responsibilities, it's more like 6-1 or so -- Cristiano Ronaldo, Steven Gerrard, Javier Pastore, Gareth Bale are all in that neighborhood. So until proven otherwise, it's hard to consider those ceilings random.
