That's a big initial bite to get down.
I played Dota for at least a year until I finally felt like I even understood the baseline. The skill cap on say SC2 is indeed as high as you can take it, but learning the tech tree and counters is comparatively trivial. It's not that Dota is chess or such, there's just a huge volume of material to get through.
But that's also what makes it so rewarding. Dota is the only video game where I feel the same sense of accomplishment when winning as a game of go.
I think the world is wide open to a new awesome RTS game. Just, no one has thought up something good enough.