Valve hasn't peddled dota for years, they have peddled dota 2 though. The big difference is dota 2 is free, with updates for free. It's also been the same game for all the years, not constant reiteration in s sets of 2. Dota 2 also has tons of dlc. Also, valve does lots of other franchises, none of which are bled out over ridiculously long duration of time.
Nintendo has other franchises too, but they're all just too saturated at this point.