I've heard that argument about Korea ever since I started following and working in eSports (around 2004ish). Yet, I'm still waiting on that big breakthrough in the USA/Europe. I'm afraid it will still take quite some time.
Still impressive numbers, but it's too easy to glance at them and think (and I'm not saying you were doing this) "esports getting more viewers than baseball!"
But in all seriousness, I think the MOBA genre may be just what it needs, whether that be LoL, DotA, HoN, or otherwise.