When did games stop being about playing games, and more about navigating windows sub folders and editing text files? I'm getting too old for these sheets.
You have been able to do that ever since there were the first game that allowed changing keys by editing text files (~80's or 90's something).
If you compare this game's way of allowing all keys and modes to be mapped and for example Turdfall 76, well, you may have to suffer once in this to set the keys but you can't ever set the (build menu) keys in turdfall and you get to suffer forever. There are also other games that for the longest time didn't allow you to set the keys, for example Starcrapft 2 and Warcrapft 3, where the default keys were set by someone that thinks it's great to be able to use abilities with keys like 'i', 'o', or 'p' for 'mnemonics' - i.e. some that came out of UX/UI school that have never played any game. Warcrapft 3 was one of those games where you could spend awful lot of time editing text files, unlike this one where you can do that in the options menu.
Let me give you an example of another stupid default setting. Every FPS game uses mouse 1 for primary fire, mouse 2 for secondary fire and space for jump. Well, I have to change mouse 2 and space because I rarely have to shoot while jumping but I often have to fire while zooming. Holding down mouse 2 to zoom adds tension to the arm due to which I lose some 1% of accuracy after 8 hours. Now imagine a piece of crap game where changing these keys lead to some other random menu to not work anymore because someone has come up with default settings that nobody is supposed to ever change (yes that game is Turdfall 76).
I'm not saying the key bindings are perfect in this game but they're a hell of a lot better than in many other games (mostly due to the fact that you can actually change them).
They could make the key bindings easier to set simply be reorganizing the menus to reduce the number of top level entries (e.g. take all 6 flight menus and hide them under a new menu "Flight Controls" and take all 6 driving menus and hide them under "Driving Controls"). One more thing that they could do is add a list of keys that are already used in any particular case in the description box (e.g. if yaw left is highlighted in a flight rotation menu, then it would list all the keys that it would override if you try to use them).