That's some friends you have lol.
Technically DotA has a plethora of different "modes" (like AR, RD, DM, etc.), they are all just slightly different variations of the main mode, using the same map, so they really don't provide much of a change from the original thing. Well actually, Ability Draft is quite different from the main mode, but it still uses the same map, but so do the "holiday events" as well, I digress.
Point is, Valve is implementing a player-generated custom game system, so soon it'll go from the MOBA with the least amount of unique modes to the one with the most unique modes, practically overnight.
Valve is f*cking brilliant because if any of those mods become as popular as the mod that spawned the game itself, they simply hire the mod team and and add the game to the Steam store. They've already done it countless times.