I was in it for the parkour; I didn’t really like the combat and kept being forced to fight people.

Part of the charm of the game was to make its combat unwieldy to push people into parkour-ing past/out of each encounter. The whole game was made so that you could finish it without ever picking up a gun.

It sounds like you didn't get far enough to learn this.

There was one fight against a boss that was a huge pain in the ass because he tackles you just as you exit a door to the roof and if you don't use the right maneuver, blam! you have to restart and listen to his monologue. Again and again and again. Dear gods, it was so bad it's actually the only thing I remember from the game.
Which is a damn shame because it really was revolutionary, the architecture is fantastic, and the parkour is flawless. Even the "you don't have to fight" thing was genuine! I literally did not fight a single guy... until that damn roof, where I suddenly had to learn the parry maneuver the hard way. Shame.

Well... the game is designed so that

1. Combat is optional

And

2. Combat is so hard you're more likely to do the parkour thing that you're supposed to be doing anyways.