For some reason, I just remembered good old Epic, a pretty ambitious 3D space shooter/sim from 1992. I found it truly amazing despite its 2D-ish coordinate system, kind of flying on a horizontal plane in space. These flight mechanics were more similar to terrain-based 3D sims (Magic Carpet) like than to true 3D space sims (Elite, Tie Fighter).
I don’t think that modern space sim fans would accept such a control system; there was enough bitching back then! However, I also wonder why space sims are not attracting much attention from games players. I am biased, of course, since I am a space nut and the first game-like thing I envisioned making with a computer was a docking 3D sequence like the ones depicted in the Galactica TV series. But it’s an intriguing idea: if players in general are being put off by the complexity of pure 6-DOF flight, maybe an Epic-like game would actually work in today’s market.
In truth, I think there are many more issues lowering the appeal of space sims. Flying sims, even arcadey ones, are not seeing much success either. But it’s a good thought experiment anyway.