If the government really got on the stick and stopped trying to reduce every issue to the correct set of tax incentives/penalties, we could make the tax code something regular people (or, at least, less than a suite of specialized accountants) could understand. This would simplify both compliance _and_ enforcement.
I want the IRS to have enough resources to do its job thoroughly, but we give them $13.7b/yr already. I have a hard time believing we couldn't do the job for that if the policy were sane.