Today, I've once again attempted to configure my HOTAS (Thrustmaster Top Gun Afterburner II) for KSP. It was a frustrating nightmare. While it is possible to somehow, with lots of fiddling, assign the correct axis... having to go back and forth from main menu and gameplay [load savegame, go to runway, quit to main menu, go to settings, repeat] is incredibly bothersome. Especially when stuff you see happening in the game just doesn't add up at all.
With a centered stick, the indicators for YPR just went nuts. Going fom far right / bottom all the way to far left / top, and wiggling the Joystick around caused them to eventually swap sides - and stick there. Y far left, P pressed down, and R far right - one wiggle of the stick and some of those swap sides. Impossible to center anything. And this has been a known problem for years by now:
I've attempted to read up on what the heck's going on here, and it seems to come down to Unity reading either raw or direct input, can't recall which one it was, while lots of Joysticks provide the other. There are "workarounds" which include disabling basic driver security measures of Windows, and installing virtual Joystick programs to serve as input to the Game while reading the actual Joystick input and putting that through...
Long story short, I'm a software dev myself looking to play a game after a long day at work. And I'd prefer the game to "just work" (in regular Windows terminology). As in: Plug, wait a second, and play. No nonsense with disabling system security components and externally emulating virtual sticks just to get a darn Joystick to work in a game that you'd expect requires one to play properly in the first place.
If Unity presents these kind of barriers to Joystick usage, it'd be somewhere on top of my priority list to work around these barriers and get Joysticks to "just work as expected" ASAP. In my time, I've played X-Wing Alliance, I've played the whole X-Series, MS Flight Sim and even TIE FIGHTER for DOS on Joysticks [even this particular one], and many, many more. KSP being unable to handle Joysticks at all, for whatever reason really, looks incredibly pitiful. I enjoy playing KSP immensely, which is the only reason why the lack of Joystick compatibility "out of the box" bothers me so much. Please don't expect your community to have a degree in computer science to just play a flight sim (be that with planes and/or rockets) with hardware made for flight sims.