Skial

I tried MobAs, I might add, and I didn't really have much fun other than with Smite.

I think it's because people enjoy the fast paced action but still want more of a strategy element than an FPS. MOBAS are generally good indicators of overall video game skill; they require fast reactions, strategic thinking, teamwork and minor amounts of grinding. It's like a PVP MMO where grinding is a very short amount of your overall playtime. People like that.

I dunno dude. Thats just what I think the appeal is.