The Marvel side is definitely kinda shitty overall.I'm taking all of them combined as a whole
Like I love X Men and Spider Man characters... but almost all of those polls are filled to the brim with them. One of the list has Venom, Carnage AND Anti Venom in the top 10!!! Not enough diversity in universe representation in the Marvel poll but that just tells you that people care more about X Men and Spider Man than the MCU (on gaming forums at least). I think the list would change if taken these days though, most of these polls were taken around the time the first Avengers came.
Marvel Infinite has the polar opposite problem...no X Men, FF or Spider Man characters (yet at least).
The Capcom side is basically what I expected. UMVC3 already covered most of the main stream Capcom characters, beyond that you start getting into some really obscure stuff on the Capcom side and by then you get extremely subjective because everyone has their own obscure Capcom franchise they want in the game.
Like look at the number of votes past MMX and Gene... you are barely cracking double digits in votes.