It's gonna be the KOF that has staying power, but it's definitely not gonna be remembered as a game that was easily approachable, more so than the other games. XIII had a lot of exploits with HD and that did sour the game for some people. I know personally that some people didn't like it because the game didn't have much in the way of good buttons and offense that you could people get away with because your buttons weren't good.
People who also tried to take the game seriously and try to play it just got fucked up by series vets. A lot of the players that played XIII felt frustrated because they couldn't deal with the onslaught of J.CD hops and general reckless play when reacting.
But KOF has always been that sort of game. It punishes bad fighting game habits and makes you pick up new ones, like running under jump ins and punishing them with a normal instead of trying to me A2A.
Also the tiers in this game were skewed.
Why would you use Joe over Hwa or Ralf over Clark? They had better normals and options that made Ralf and Joe not much of a threat in comparison. You could still use Ralf or Joe, but it's like picking picking vanilla ice cream over picking vanilla ice cream with chocolate fudge at the bottom of the cone.
imo, the game is fun, it's enjoyable still, but it did have its problems and the support SNK "did" for the game really didn't keep it alive. If they update the game right now and took out all the crap in the game, like the infinites, hitboxes, and damage on HD, it still would've kept going strong, buuuut it didn't, and now it can be found at a bargain on steam for 80% off.
Me personally, I didn't mind the damage. If I got hit and died, that was my fault. What I DIDN'T enjoy is not being able to defend myself with AA normals that didn't work and I died trying to tag somebody out of the air for abusing hop CD too much. What I also didn't enjoy was the stupid hit stop delay after a Guard Cancel Roll, and it literally just read Close C, and that was my high damage punish.
XIII was for what it was a game that OG FG fans say is a good game on the surface, but people who dug in to the game more and more found some critical issues in the game's design that made it fugly. I'll still play it, but I won't enjoy it as much as I do other KOFs.