I think that this is because MOBAs are (unintentionally?) more like a sport with positions, teamwork, etc. I think that leads to MOBAs being more exciting for a mainstream audience and we see huge hits[1], where RTS is more for the niche audience that you saw for PC games 20 years ago-people who are more excited with honing computer skills than communication skills. I fall firmly in the latter camp, but I see why the market favors the former.
I totally agree about the 'being able to play again at will' part. That's what drove me away from LoL when I tried it-it was my very first game, I wanted to walk away, and the interface told me I was hurting the community by leaving early. I took the hint and decided to quit playing entirely. I don't want that kind of responsibility-the whole point of a hobby is that there aren't consequences for failure (or at least I've seen it formulated as such.)
I totally agree about the 'being able to play again at will' part. That's what drove me away from LoL when I tried it-it was my very first game, I wanted to walk away, and the interface told me I was hurting the community by leaving early. I took the hint and decided to quit playing entirely. I don't want that kind of responsibility-the whole point of a hobby is that there aren't consequences for failure (or at least I've seen it formulated as such.)
[1] Well, one huge hit