Add a Parser that only the player can see.

[Viridiana]

It'd allow folks with poor DPS to actually see they're doing poor DPS, and would (hopefully) encourage them to seek information/assistance to see how to fix it.

Only if there's no option to turn it off (else they'll just turn it off because the hate the very idea of parsers), and only if they're somewhere informed of what baseline they should be hitting (because the numbers are meaningless in a vacuum).