Partially this, the AI was never changed to adapt to the patch and tuner changes (specifically the stamina tax on backwards movement, slowed movement while blocking and a few other stamina changes)
The other thing is you really need to drop the output slider to minimum to even have a chance of realistic output, and even then it was usually only against counterstrikers.
And finally, you kind of have to go to 2 minute rounds for the AI to not gas by the 6th as a general rule, but once you do, 12 rounds of sweet technical war can happen.
But in short the patches didn't do much good for the AI, but sliders can help a lot (Output:0 Defensive Awareness:7 and Offense Awareness:8 off the top of my head)
I still occasionally uninstall the patches and play the vanilla version on 360. The AIs better and the block "parry" counters were kind of fun, and the fact that the patches completely broke the swelling and cuts (specifically the swelling outside of bare knuckle)
However the patched version is better gameplay wise, you can cut angles waaay better, the stamina feels more realistic, movement has a stanina tax and they made it so hugging block slows your movement speed so you couldn't effectively block and run, which was way to effective in vanilla.
God I wish/hope ps4 gets it somehow..