Street Fighter 4? The only thing I can see that's "simple" about this game in any way is that there is a cultural burn-in and usable muscle memory for the world warriors' special moves. Beyond that, it's a pretty fucking complicated game.
What's utterly fascinating to me here is how Capcom managed to effectively convince people that this game was really casual-friendly and easy to get into when so many less complicated fighters have not.
It's a marketing point. It's a communication tactic. And it's something that a lot of games obviously fail at when they shouldn't.
If you ask me, constructing a less complicated or frame-specific fighter isn't even remotely necessary. What these companies should really get after is figuring out what it was about Capcom's communication and marketing efforts that completely altered the physical reality of their product into something that people are willing to swallow.
That communication is obviously the ticket to broader fighting game success.
I'm not being even remotely sarcastic. After listening to the mainstream media reaction to Sf4, I'm utterly convinced that it's less about what you give someone, and more about what you can make them believe that you are giving them.