what some people don't realise is that MOBAs - played at a high level- aren't a game anymore, they're an e-sport. They are played competitively, the only goal being to win. This applies to HON/DOTA/LOL, but also to Counter-strike, Starcraft, and, to a certain extent, Halo. Obviously also to Quake and UT, but those are to old to be relevant now.
An e-sport is taken as seriously as competitive sport in the USA. Any American will know how important winning is in sports. To understand the importance people attribute to winning in some video games, you have to see them as an e-sport.