> but it's never been big enough in League that I felt the effects.

Hm... Have you ever played in ARAM? ARAM is mode where you have only one line with 5vs5 players on it. Often it's much shorter than regular Dota, LOL matches but give same "experience points" to buy/open some in game items.

You can encounter farming bots there, they just do one thing : go to enemy and die. It isn't fun to play with them. Once there were 3 bots in one match. Servers were infested with them for weeks it was impossible to play ARAM back then.