It's not about losing everything. Being able to die is not required to be qualified as a game in my book. But some form of failure is.
In WoW, you can never fail at anything. You can always try again, without being set back at all. In EVE at least people can steal your stuff when your ship is destroyed. This makes you want to prevent being destroyed. In WoW nobody cares if their character dies, because it has no consequence.
there are consequences just minor but it does set you back, also your line about not failing in wow because you can "try again" if you have to try again.. you failed the first time you tried.
Beware of the Turing Tar-pit in which everything is possible but nothing of interest is easy.