They compare it because it's similar with DOTA, but not a clone of it. It's the same type of game, and this type of game needs a lot of heroes, not just 8-10.
Why Demigod needs lots of heroes?
Because DOTA had it?
Simply ridiculous, this ISNT DOTA, and 8 heroes are just fine, there are tons of things to do to this game, and the LAST is adding heroes.