No point in cancelling certain policies

Consider this screenshot:

As you can see, reducing the previous level to 0% will return all the green and red bars to their neutral value (notice the very small lighter shades in the bars at 2% policy strength), which I imagine is what cancelling the tax would do. Only cancelling it costs 30 political capital while lowering it to 0% strength costs 10, and I get ~3 billion income to boot. I believe this game mechanic is broken!

Changing this would complicate the budget, but it’s quite a simple fix: for each tax policy, include a base cost that rises moderately with increased slider usage. At zero slider, the tax will (in many, but not necessarily all) cases be unprofitable, so that it’s better to cancel it outright. This models the cost of collecting a tax, even a minimal one.