The league has a ways to go, but I think you would have to be willfully ignorant to not see that the sport as a whole is really starting to catch on in the U.S.
I really don't think it is at all. Seattle is an outlier due to them losing the Thunder nee Sonics. As for the Red Bulls, they're attendance is all right, but if Brazil/Portugal plays in the Meadowlands/RBS all the people from Newark/Surrounding areas go apeshit. American's biggest soccer fans are the immigrants and they really don't care about the domestic league.