Georgism is not about scarcity, it's about economic land: inputs to production which are fixed in quantity, and that you can't make more of. This is a very different characteristic than scarcity, because many scarce things can be increased, and should be if they are needed.

Taxing specialized labor goes against that spirit, because specialized labor can be created. And in fact taxing the labor would result in less of it being there, the exact opposite of the optimal result.