Quake was good, but FPSs have evolved, and are much more than just running down corridors shooting with a different variation of the same weapon.
If Quake was the be all end all, it would still be being released as we speak.
In terms of skill the FPS genre has degenerated massively due to the influx of casual players. I know a lot of great players are fans of it, but I really do think Counter-Strike and its "newb" rewarding random shots have pushed FPSes to where they have evolved today. Don't get me wrong, I enjoy modern day FPSes also, but they don't require you to have inhuman reflexes and god like awareness of the map to be number 1 any more.
My nephew who is 14 considers himself AMAZING at Halo and all the modern day FPSes, whereas I find almost all of them completely dull and slow (save Battlefield series mainly due to just the ways you can create hilarity). He loaded up Quake Live for the first time and he just couldn't keep up saying "wahhh its to fast how do you play this" and his jaw promptly dropped when I got in there and started doing my thing. I then explained to him there are people a LOT better at this. He just can't understand it and that's how most gamers are being brought up this generation.