I'm eagerly awaiting the day that space flight sims (and mech sims, for that matter) make a comeback, but I completely agree that the space sims of old had big time accessibility problems.
I remember Freespace 2. It was one of the most awesome games I'd ever played, but it was just. So. HARD!!!
Probably half the missions I played in that game, out of multiple wings of fighters that my side fielded, I would frequently be the only pilot left, completely out of ordinance, outnumbered 20-to-1, and having to blow up a small cruiser on my own. And this was on medium difficulty! I can't even imagine how good you'd have to be to play that game on maximum difficulty.
I fully admit that I probably just didn't 'get' how to play the game (I had similar problems with the X-Wing and TIE Fighter games, mind). Perhaps it was because I hadn't cut my teeth on Jane's combat simulators like some of the adult gamers, but for me the hardcore space sims of yesteryear will most likely be forever beyond my ken.
I remember looking for a FAQ on TIE Fighter on the Internet, and happening upon a graphic of how you're supposed to evade a concussion missile. It looked like it had been drawn with a Spirograph. As Oscar Wilde was once incorrectly paraphrased by Yahtzee as having said, "No chance, you unreasonable dicks."