Comparative. A green and some silver is a greater reward in a world of whites greys and copper pieces
I guess (as always) we'll have to disagree about the risk of death in retail. Although its hardly surprising you leapt to comparing retail's raiding and disregarded the levelling; there isn't a great deal to the game other than that huehuehue. Incidentally unless they've revamped the questing experience for Legion, its still pretty fucking impossible to die even without heirlooms in the open world. You pretty much have to be AFK or intentionally trying to kill yourself
(One of the -to their credit- things that the revamped questing did to cata was unify the rewards a little better so that doing a couple of similarly levelled zones would reward you with most of a set of armour that looks the same; I actually quite liked the blue colouring of the thousand needles/hinterlands(? think) mail armor set you get as a reward
So I've levelled toons w/o heirlooms and it is a walk in the park comparatively)