Ok, so I'm kind of taking the bull by the horns on this question, but it's something I've been thinking a lot about lately and something i'm having a hard time finding an answer that isn't 'cuz people who play League are gay'.
I'm a League of Legends player with close to 2000 games under my belt, I've gotten to the point where I can confidently win my lane in all positions in most matches and don't really remember the last time I was called a 'noob'. I've put in time, practice and have a pretty good handle on how the MOBA genre works on a micro and meta level. It also, in fairness, makes me incredibly bias to League.
I have a few friends, who haven't played MOBA games before, get into Dota 2 recently and i've tried to join in with them, but I'm having a hard time having any fun in Dota 2. I've played about 20-ish hours so far. I fully accept that the skills don't transfer very well as there are a lot of different mechanics present in Dota 2 that aren't in League and vice-versa but in comparison, the characters movement isn't snappy and the extra mechanics so far, seem archaic and an unnecessary barrier of entry. Is denying really a fun mechanic in practice? Does the lack of free teleports-to-base in Dota 2 really add a necessary layer of strategy? I'd like to point out, however, I think Dota 2 is extremely well made - this isn't me knocking the game.
I'd love to talk to someone who has played a lot of League of Legends and made the switch. I'd love to talk to someone who can give me a convincing argument to stick with this game. So far it seems like the only reason to play Dota 2 is if you had played a lot of Dota Allstars and have the mechanics ingrained to your brain. I played a game the other day that we had clearly lost at 8 minutes and the enemy team dragged it out for 45 minutes. Without League's surrender option. I haven't got a desire to log in again.