Why? It's garbage. Even if you are at a low enough level where you wouldn't otherwise have an earring, 2 stamina is unlikely to result in many hitpoints. I gave one of these to my level 6 alt...didn't gain a single hitpoint.
The 2pp you would spend on this would be better spent on a pair of Dervish Cutthroat Insignia Rings, which at least give AC in addition to their pitiful stat bonus.
Grimveld Grimforge 31st Level Paladin of Ayonae Ro
My enchanter made a pair of these while he was working on his jewelcrafting skill. Gave them to my monk, which increased her hit points by 8. That's aabout 2HP per stamina point. Not great, but more useful than the sapphire earrings she was wearing, which were better suited for a caster, so I traded the earrings between them. Once I'm good ebough to replace them with platinum, or some cougar claw earrings, I will. I agree though, 8HP for a level 32 monk is nothing, really.