Most rewards in gw2 are skins, dyes, and gimmicks. After just a year or two of playing gw2 the skin unlock of a random new rare item is more interesting then the item itself.
Skins, dyes, and gimmicks are important enough to some players that they spend real world money on them in the gem store, or real time grinding resources for them. Their value should not be discounted just because they dont provide gameplay content.