Will some games need more sweat and tears than other games. SFIV, MvC3 these games dont need as much dedication as KoF XIII. The easier it is the better for people these days because they are just damn lazy!
Honestly, it's like comparing apples and oranges. While I do agree it's easier to get good in dumb games like SCIV, Brawl or DOAIV, SFIV and MvC3 are just as skillful to play but in different areas. Like I said before, SFIV is all about tight links, matchup awareness and plenty of footsies. Marvel has always been about juggling mass amounts of information and being able to execute when there's mass hysteria and lightning speed conditions. So one is basically the equivalent of sheer boredom and the other is decided on how much bullshit your team can do.
Trust me, it ain't anything but easy, I've been there. You need to know your stuff, there's no need to judge, it's all a matter of taste in the end. Even KOF doesn't appeal to everyone. Not everyone loves the anime characters, the furious rushdown and the sheer brokeness of some characters in the series like Krauser, vanilla Raiden and Nameless and how they are not banned.
After being exposed to the tournament circuit, I've grown to respect and appreciate different games, even if I like making fun of them and actually hating some of them. Like I said, I ABSOLUTE DESPISE PLAYING SFIV, but I have to respect its community, because they're legit and it's just my opinion.