Clearly you must play a lot of LoL at a high level to know so much about it.
I play both games, and the style of each game is different, but they are both fairly complicated. Is LoL easier to pickup than DOTA? Yes. Is LoL an easy to play game? Hell no. If it was, pros from the DOTA scene would play both games and make a killing doing so.
Dota is more complex, but a lot of it is arbitrary "hidden" complexity. This is due to engine issues that carried over from War3. Even the creators have acknowledged it and are working to remove some of it (see last set of patch notes). Things like "oh this spell works through BKB but this one doesn't", or this spell does some weird mix of damage types, etc etc.