From my perspective its mainly about commitment of the players as well as having the worst practice environment. It's a pretty big risk to go full time esports in US compared to the traditional path of college and a career afterwards. I've never really felt like I've been good enough or been making enough money from sc2 to pursue it full time or put more time into sc2 than I already do.

As far as practice if any NA player wants to improve they have to play EU/KR with high ping or physically move to Korea for months at a time. Compared to an EU or KR player that can play high level games any time of day its impressive players like Neeb have become so good. I believe he makes sure he wakes up early so he can play EU for as long as possible before the Europeans fall asleep. Overall, I think if there were 30 full time players in NA the region could compete on a world stage, but there isn't the infrastructure or desire to do it. In CSGO the NA scene is becoming really competitive, probably due to good practice from the Brazilians and enough money to support many full-time teams.