WoW"s death penalty scales, which is important to remember. For the average player, it"s a PITA but not a game buster. You have to run back, maybe rebuff. The catch is in dungeons, where there is a possibility of respawn. You die for 2 hrs, no biggie. You die beyond that, and shit starts to respawn and you have to reclear.
For raiders, you lose out on LOTS of gold (repairs + consumables) + you risk reclears for certain encounters. This is magnified by your raid force...you might not be bugged by it, but keeping 25+ players motivated to keep playing that night becomes harder and harder.
The golden rule I think needs to be remembered is that, in the end, it"s a game. Games, usually, are supposed to be fun When the game starts to feel like a chore or a job, it"s not fun anymore...and you"re more likely to stop playing. For games like EQ1, this was a problem because the chore/job was a core game mechanic (kill stuff). I do like the freedom in WoW of being able to just log the fuck off when I get really frustrated. No having to stay around for CR, no begging/pleading for a rescue/res, etc. You lose at your present goal, but your guy will still be there in the morning ready to tackle it again (although with raiding, this requires more farming/gold...). EQ1 was always a chore...I hated those damned 4 hour CRs going on past midnight, when I just wanted to goto bed.
you die, ghost back to your corpse and lose a few coin, or just summon your corpse to a GY. yeah, that"s real risk there.
If you"re just diddling around doing PUG crap, sure. But WoW does have a pretty harsh raider penalty: You don"t get your mob, and you gotta farm alot. In a way, that works well. Raiders usually = hardcore, and hardcore = the ones who want to be punched in the nuts with a hammer.