I may be mistaken here, Jerykk, but I think you're saying that we've lost all these types games on the PC, right?
Well, you're partially mistaken. Some of these genres still get a good game on occasion but it's too rare for the genre to be considered alive. It's like a corpse that occasionally twitches.
Vehicular combat games - Ehhh, what are these? I can't even think of one.
Interstate '76? That was a classic. Unlike Twisted Metal, it actually felt like you were driving a car and it had depth. We need open-world, vehicular combat games with RPG aspects and good driving models. Unfortunately, the last vehicular combat game that comes to mind was Hard Truck and that was pretty bad.
Space Sims - The X series is doing fine. Their next title was recently announced. And while few here care for his games, Derek Smart seems to be going fairly strong still. I wouldn't exactly call this dead.
I'd call it dead when no American developer will even touch it and the space sims that do come from Europe are, for the most part, crappy and unpolished. Whatever happened to Freespace 3? Or Independence War 3?
cRPGs - Witcher? Mask of the Betrayer? Two worlds? That's just what's been released last year.
Witcher was a great game. Mask of the Betrayer was an expansion pack to a shitty game. And Two Worlds was a very shitty game that had more in common with Diablo than any actual cRPGs.
Shooters with depth - What's wrong with Crysis? It runs like a one legged whore with a broken back but I'd call it a pretty deep shooter? Large open areas, the suit powers that actually make a big difference on how you play. And what about Bioshock? Giant underwater station that you can walk back and forth in plus plasmids plus ton of weapons plus upgrades plus being able to use the environment against your enemies not good enough?
Crysis wasn't really deep at all. You either play stealthy and put up with completely retarded AI or you go blow everything up. There's not much meaningful choice in the end.
Bioshock was a watered down (all pun intended) version of System Shock 2. No RPG aspects? Check. Respawn chambers every five feet? Check. Overpowered plasmids? Check. Lack of plasmid and enemy variety? Check. Plasmid choices that can switched at any time? Check. Weapons that can all be fully upgraded by the end of the game? Check. No inventory? Check. No challenge? Check.
Bioshock was also designed for the 360 so it doesn't really count as a PC game.
or incredibly quick, high-flying action - It's funny because you mention UT, and we just had the umpteenth iteration of that game released. Also, Team Fortress 2?
UT3 is fast, yes. However, it's probably the last UT we'll ever see. It also has a heavy emphasis on vehicles which have no place in fast-paced, over-the-top shooters. TF2 isn't fast unless you play as the Scout. Even if you include TF2, that's two games... out of how many slow, pseudorealistic military shooters?
Off the top of my head, 3 long time PC Franchises are actually being restored this year. Fallout, Starcraft and Deus Ex.
I don't actually consider them restored unless they can at least live up to the previous titles. I doubt Fallout 3 will be as good as one or two. And no, that's not because of the perspective change. I'm happy with that. It's just that Bethesda's previous RPGs have shown a complete lack of meaningful choice, the very basis upon which the original Fallout was built. I highly doubt Deus Ex 3 (which won't come out until 2009 or 2010 if EIDOS is to be believed) will even come close to the original, as it's a multiplatform title and most likely being led by 360 development. As for Starcraft 2, well, I suspect it will live up to the original.
Now let's look at some of the franchises that have been (or will be in due time) raped for the consoles:
Rainbow Six
Call of Duty
Ghost Recon
Longest Journey
Mechwarrior
Commandos
Elder Scrolls
F.E.A.R. (Project Origin lead SKU is 360).
Thief
And of course, Deus Ex.
Are we veteran PC gamers jaded? I guess. If jaded means that we once played great games that haven't been matched since, then yeah, I guess we are jaded. As with any medium that grows increasingly mainstream, the quality of games has declined over the years. When developers didn't try to cater every game to retards and grannies, great games were made. Great games are still made now, only far, far less frequently.