You could take this argument all the way down. Why did valve pick it up? I don't think they saw dota2 as a profit engine necessarily, though there is some argument for that. The company does tend to engage in bus ticket obsessions (VR, dota2). Sometimes it fails (artifact). But I strongly suspect that Gabe Newell bus tickets dota2. I would guess that like myself, he has no real skill at the game, but he just loves it. And he hired the guy (icefrog) that bus tickets dota2 mechanics. The combination is an enormously entertaining (for us fans) wildly unlikely tournament that has a 30 million dollar purse.

Tarn and Zach Adams are also bus ticketers.