Go to work as an inner city teacher? Here's an extra 20% in your BI.
Live in an area damaged by a hurricane? We'll bump your BI for a year or two.
I don't think a "simpler" tax code would last much longer for the same reason.
The only way I think it could actually work is if we turned over the whole thing to a bunch of unelected technocrats like the Fed (which might not be a terrible idea since it gives them another lever on economic policy...)