I'm not super surprised by this but playing Killer Instinct a little more, it don't seem like a game for me. You'll hear more of my thoughts about the game when I bother writing about it in a blog post.

GranBlue Fantasy Versus Rising is in a similar boat for me, I started playing that game not too long ago as well.
Interested to hear about what didn't click for you! Every time I think about KI I keep thinking I should play more KI...
The main 2 things that stick out as not to my taste so far are the movement, I prefer games with stronger movement, and this might sound incongruous but my other issue is that the game-speed is faster than my liking.