Zenchess: I looked at the games in Linares; of 42 games in that tournament, 14 were draws under 25 moves or less. Of those 14, 7 were by Kramnik. I looked at the final position in each of these draws; in all but one of them, Kramnik could have played on:
Round 1 vs. Vallejo Pons: Playable; Kramnik could have tried the pawn break 18...f5!?
Round 2 vs. Shirov: Kramnik may very well have tossed away a point here. With 22. Nc6!, White has all sorts of compensation for the e-pawn Black is about to take. His pieces are much more active than Black's counterparts. Knowing how Shirov hates defending, he may have worn down here.
Round 3 vs. Rajabov: Kramnik may have had an isolated double, but if anyone was better in this position, it was him. With 24...Qd3!?, Black temporarily sacrifices his c4-pawn to gain Rook penetration to b3; he will soon regain the pawn with more active play.
Round 4 vs. Leko: This is the one game where he was right to take the draw; Leko was about to create a central pawn roller. Had Kramnik played d4 himself, Leko captures twice on d4 and plays...d5, creating a dangerous passer.
Round 8 vs. Vallejo Pons: Playable; 21. Bd3 was possible to target the e5 pawn.
Round 10 vs. Topalov: Kramnik came under some pressure against his K; however, ...Rb8 preparing ...a6, ...b5, and ...c4 counterplay was possible.
Round 12 vs. Kasparov: Playable; Kramnik had play against the isolated c6 pawn. Even Kasparov screws up the ending sometimes; once, he lost a drawn R+4 vs. R+3 ending. You can never beat the World #1 unless you set out to do so.
In these games, Kramnik showed a clear lack of fighting spirit here. I'm not saying he was better in these positions; however, there was plenty of reason to play on. So not all the GM's in Linares showed a lack of fighting spirit; however, Kramnik did.
If you want to study someone with fighting spirit, only a little over 10% of Korchnoi's games were quick draws. Only 5% of Bobby Fischer's games were quick draws. By contrast, almost one third of Petrosian's games are draws of 25 moves or less.