Coming from League dota 2 can be a a shock to the system, Couriers, buybacks, death penalty oh my. It can be a lot to take in for a league player that is more familiar to the simpler ways of Riot game but once you put some hours into the game you can see the care a dedication Valve and icefrog have put into the game. Replay system, stats tracking, pro guides,spectating friends etc and all of this at the flick of you fingers. The game is so well put together that I find my self sometimes just navigation the menus and watching friends play because of the ease of it all.
AS for the community and heroes of Dota 2 , Heroes are very unique and complex that it makes even supports feel fun. Even more so than in league that most support are just heal bots or babysitters. I never had so much fun playing support that the role I mostly play , something that in league feels tedious and boring.
AS for the community side of things I actually have to say that I have less troll show up here than in League and that in part of Valve strict and swift punishment of muting trolls and angry gamers for very long periods o f time.
In all even if Dota 2 does not replace League for you , it should at least warrant a try. Who knows you might be surprised.
P.S also you have all the heroes unlocked from the start and no grinding for stupid runes which is a plus.