This is a misleading topic.
Whether something is a "sport" (electronic or not), is a definition. Belief doesn't factor into it.
I'm going to link a rather well written article that covers essentially all of the commonly accepted definitions for eSports:
http://www.teamliquid.net/forum/general/335391-the-definition-of-an-esportI'm not intimately familiar with the League Pro Scene, but I'm pretty certain that it'd meet the criteria for at the very least definitions [2] through [4] in the above article.
Funny little universe you live in where DotA/DotA2 are eSports and LoL isn't. They're both just onehand noskill MOBA trash that should die in a fire, but apparently people love to play and watch that ****, it sells, and can feed progamers, so sure, they can be eSports too.
tl;dr, i think that if people play it competitively at a professional level, and people watch it, it's an esport. The feeling I get from your post is that you're insecure, and want to feel some sense of superiority over the lol-playing-plebians as the dota-playing-master-race. Pardon me if I'm wrong but it sure came off that way.
RE: Selling out
err wtf? I don't see how any corporation willing to inject money into the scene is a bad thing. it pretty much needs to happen for heck, any sport to be viable. If noone was willing to throw money at it to sponsor events there wouldn't be prizepools etc. In the end, if the game's a flop and nobody watches it the "problem" will sort itself out anyway, wouldn't it? The very fact that they can continue to do it is attributed to some success somewhere - something's going right, no?