plenty more people want to moderate, seriously, why should they pay them? hear me out:
If you pay them "a livable wage" you'll get people in the chair who don't want the job, just the pay. If you pay them less, suddenly you'll run afoul of minimum wage laws, overhead of having employees, etc.
you could auction off the job (mods pay reddit for the privilege, given that more people want to moderate than currently can) but that would encourage the mods to monetize their sub (the more successfully, the more subs would become part of ebaum's world)
voluntary moderation actually is the happy medium, people who love the job and the sub are willing/want to do it.
Like they say "everything can't be measured in money" (ok, I never say that, but there it is)