[charlesdm]

Getting audited is bad, why? The point is: can the IRS make their case and prove that whatever behavior by a taxpayer is not actually sound and proper?

If you make a seemingly reasonable decision, even with an ultimate (very) beneficial tax outcome, there is not much that can be challenged if no laws have been broken.

Add to that the army of lawyers that on meaningful cases will keep pushing things out forever, and you should have an understanding as to why tax authorities around the world do not like to challenge the very wealthy that much. They often also control companies and assets that employ people, which can be used as leverage in negotiations.