DOTA is stale because the MOBA genre is saturated.
DOTA is a great game, I've played over 1k hours on it in a year...when I was playing it was everything I wanted a team-based game to be. Now I think everyone jumped on the wagon and therefore DOTA lost its edge. I am still a loyal DOTA fan, I think the game is one of the greatest I have ever played. But until the hype returns, I dont think its future is very bright.