Good blog post, but here're my qualm with the arguments.
You're operating from the standpoint that Street Fighter IV was supposedly simplified to appeal to the masses. I disagree. Street Fighter IV was supposed to be an easy and intuitive gateway back into the fighting game genre. And this was accomplished by appealing to various levels of play.
The focus attack deceptively complex, as you suggest, and the parry is deceptively simple in concept, but you're forgetting that the ease of execution of these on a technical level leans towards SF4. The timing is more forgiving and the risk is not as severe.
This is not to say that Focus Attacks can't be used in a manner that is time sensitive and risky (just watching any Poongko video can squash that theory), but the point is that people can still use Focus Attacks on a very basic level. Parries cannot be used on a very basic level at all.
EX moves make sense and were never complex. You press one button, it does the normal move. Pressing two will do a more powerful one. It's logical, and most beginners are able to understand that. EX moves weren't an issue in SF3... it was using them well and in the right situations, which remains an issue in SF4.
The EX cancel doesn't have to be used (and is really more a part of advanced Focus Attack usage anyways).
The Revenge Meter is a nice touch. It's really the beginner's super meter, able to change the tide of a battle is a single move and they don't have to do anything except get beat up in order to earn it. More advanced players will focus cancel to get Rage and be able to combo into Ultras, but for the most part the Ultras can't be comboed directly into (except after a level 2+ Focus Attack)... and Capcom did this on purpose, so that you would have to bide your time and wait for your opponent to make a mistake, not just whip out a move and win the game.
SF4 affirms that old mantra of "easy to pick up, but hard to master." It's learning curve is steep, but can still be enjoyed without learning anything at all. Everyone can enjoy SF4 on their own level, and THAT's what separates it from the many other fighters (where it becomes button mashing vs. expert juggles).
The game simplified things in the sense that ONE move changes the entire gameplay mechanic. The Focus Attack is a single powerful move, armor properties, induces stun, a form of parry, a combo cancel, a bait move, and a mind game all in one. It's very flexible and complex for advanced level play, but seems simple at first glance- exactly like SF4.