I don't think that's the case. Or simply from my own perspective. I use to be pretty good at Starcraft2 (like top 0.01 percentile according to ladder, which had me playing vs grandmasters and pros often), but I was never any good at games like Dota2 (game in which I have more than double the hours of SC2).

I think the main difference is that in team games its much harder to figure out what you are doing wrong as you're not the sole contributor to the loss. If you lose in 1v1 in Starcraft, you can watch a replay and pretty easily find out when you lost and why. And with team games like MOBA's you have 10 variables, instead of just 2, so it's always combination of things that went wrong. Another big deal is that you have to master 1 race in RTS and you have a pool of 100 heroes to learn, each with unique mechanics.