A few of the reasons I think SF4 is king:
- The animation is unparalleled. It's very satisfying.
- Facial expressions and reactions to hits are best in class. This is incredibly important.
- I love taunts and they put an enormous amount of them in.
- Focus mechanic is really cool and adds depth
- Characters play very differently from one another and are well-designed.
- The game mechanics are good. Avoiding long combos is a smart thing to do.
A few of the drawbacks:
- The timing is too tight for some links. especially those using LK/LP. Execution should be easier and require no time in practice mode.
- There are too many characters. Sounds crazy to complain about it but it's true. It prevents people from knowing every matchup and becoming proficient with all characters.
I'm not trying to shit on your opinion but almost every positive you've listed I vehemently disagree with.
- The animation is not great. Kinda' jerky looking. It doesn't look fluid at all. In fact, characters look rubbery. On that note; character models look hideous. For a 3D fighter that came out in 2008 (originally) it just looks bad. I think Capcom was going for a pseudo-2D look and it just didn't work out. I'm not against 3D models at all. I think Virtua 5 (which came out originally around 2006) looks A LOT better than SF4. Any other 3D fighter looks better by comparison.
- Taunts are fun but they serve zero purpose in terms of gameplay (aside from Dudley's in Ultra). I think adding a dozen taunts is kind of a waste of resources.
- I dislike the Focus. It feels safe and random. It's more character specific but Focus just feels like a YOLO tool. Just throw it out and hope for the best. If you guessed right, you get to do a combo, if you guessed wrong and they block then no biggie you're still +1 on block. It's difficult to punish a whiffed level 1 Focus unless you're really good at reading or they did it as an AA.
- Not really. There's a handful of characters who are fairly unique (Viper, Fuerte, to an extent Abel, Hakan, maybe Gouken, and that's about it) but there's a ton of characters who play very similarly. How many Shoto's does SF4 have? 8 different Shoto's (counting Sagat and Dan). Have. Fucking. Mercy. Then you have 3 grapplers with the same basic move set and the same kind of AA and standing Grab Ultras (Hugo, Gief, and Hawk). And a bunch of other characters that we've seen before in other games but with different properties.
- I think the game mechanics are ass. I used to think it was an easy pick-up-and play fighter and there's certain mechanics that help newbies but for the most part I don't believe it's an easy game to pick up. 1-frame links are not easy. And I can't think of any fighting game before SF4 that bases it's entire combo system on 1-frame links. Why Capcom/Dimps went in that direction I have no idea. If you want to get even decent at SF4 you NEED to learn the 1-frame links, no ifs ands or buts. And because of 1-frame links the reversal system is crap. Someone doing a blockstring? Mash out. And 1-frame links work so well in Delay-Based Netcode (said no one). The Ultra system sucks. No one likes it when a dude guesses and he does 50% damage. Throws are slower than other games and can be jabbed out. Oh, and you can crouch-tech throws. AND there's backdash invincibility. And you have to learn how to FADC. FADC'ng on block is super easy but doing it on hit? That's going to take time. Plus you have 40-something characters and have to learn those matchups. It takes time to learn even just one matchup against a certain character. Now you have to learn 40+ character matchups... Not to mention all of the Option Selects that are a thing and you need to learn them if you want to be decent. Why are there half a dozen Option Selects for every single character?
I know I reiterated two complaints you had but there's more problems with the game than just 1-frame links and too many characters.
So why do people play SF4? Because it's popular, people play it, and for the pot bonus. Why is it popular? Because people play it and it's the latest Street Fighter that's out. When SF5 comes out (and assuming it's going to be significantly better on every front) I guarantee you that SF4 will die in a matter of months.
As for my pick of best fighting game I'd go with 3rd Strike. Amazing sprite work, music, voices for the characters, perfect controls, fairly easy to pick up and play (easier than SF4 I'd argue) and somewhat balanced. So long as you don't go with Sean or Twelve you have a decent chance at winning. And the characters are all varied. Ryu and Ken are almost completely different characters if you're fighting a Denjin Ryu.
I'd like to try out the Killer Instinct but I'm waiting for a PC version.