No it wasn't. It was designed to be used without a mouse, that's all. More specifically we didn't want you using an operating system interaction method to control the ship's functions when you're supposed to be pretending to be a pilot handling a ship with a bunch of HOTAS like controls. Thus everything was designed to be done through HAT switches and buttons. We did not want a mouse cursor on top of the screen in space flight as that's the exact opposite of how a pilot in this universe would interact with their ship.
No one has many complaints about the ship UI, but what about starmap and station interfaces? Those would clearly benefit from being "OS-like" over the controller friendly versions they are now. Look back at the market and orrery view concepts you guys made during KS, clearly they have been dumbed down to be usable without touching the mouse and keyboard, and since you've known the game would eventually be on consoles, being 100% controller friendly surely was the primary driving force here? Had ED been a 100% PC-game without any plans to ever come to consoles, I can assure you most gamers would have prefer controller hostile and mouse-forced interfaces for the station, market and starmap. Most PC players after all have only mouse and keyboard.
I mean, last time I checked I couldn't even accurately use the mouse to interact with the station menu if I slightly move the head of my character with TrackIR or similar, even though translating mouse position from screen coordinates to in game world coordinates is a simple thing to do
Also, if FPS mode ever comes to ED, controller users that can't easily reach their mouse will be at a disadvantage to those sitting at a desk with the mouse in hand, this will force controller users to either invest in a trackball or drop their controller and reach for the mouse. Unless of course you nerf mouse-look speed but then you'll alienate the majority of the remaining PC-player base.
So maybe I worded myself incorrectly, I should have said that the UI has been designed, and will continue to be designed so they are "controller-only" usable and that this disqualifies certain more powerful UI-paradigms but as a bonus for the developers it cuts down on porting work. But as a PC only gamer I know most other PC only gamers would prefer to drop the controller on the floor the moment they open the station menu or starmap.