You know how we can be pretty sure that the NSA's data haystack hasn't done much to prevent terrorism because if it did they'd be shouting it from the rooftops?

Well occupational licensing is the same way. If there was even a shred of a farcical bad-faith argument that it saved money they'd be happy to spout it. The fact that the proponents don't even have that and instead shove appeals to emotion in your face tells you everything you need to know.