"One piece is that forget that what we're trying to optimize is happiness, and if those 13.4% of waiters are happy, then who cares if they have a BA or MA?"
Sorry to nitpick, but this is important. Never mind whether a degree really brings more happiness - who said we're trying to optimize happiness anyway? It's certainly not what most societies try and optimize, at least not on the societal level.
Just as a simple example, sending kids to join the army is not in the best interests of the kids' happiness, nor in the best interests of the parents' happiness; yet every society chooses to do so (never mind your personal stance on the military, societies are obviously optimizing for self-preservation over the happiness of individuals.)
Consider as a counterpoint Aristotle's Politics, Vii.2: "It is evident that the form of government is best in which every man, whoever he is, can act best and live happily."
Sorry to nitpick, but this is important. Never mind whether a degree really brings more happiness - who said we're trying to optimize happiness anyway? It's certainly not what most societies try and optimize, at least not on the societal level.
Just as a simple example, sending kids to join the army is not in the best interests of the kids' happiness, nor in the best interests of the parents' happiness; yet every society chooses to do so (never mind your personal stance on the military, societies are obviously optimizing for self-preservation over the happiness of individuals.)