Anyway, I'm not economist either. Perhaps it's best if someone could referred to economic theory, instead of what feels right.
Why not tax cigarettes, soda, pollution, and other bad things. The dead-weight loss from the tax is actually a good thing in these cases.
Agreed that there are always unintended consequences, I don't really know for sure, and democracy is unfortunately usually about feelings.
In the case of income tax, you raise revenue but you change behavior in a negative way (discouraging work). If you instead tax vices and consumption, you can raise money while not causing negative behavior changes (and maybe instead causing good behavior changes).
However, as the parent comment pointed out, you have to really look deeply at a tax to figure out how it will affect behavior. It won't always be in the desired way.