From one of my accountancy guys:

Mr. Goldberg:
I think you are correct in stating that the result of the KPMG case is the result of an unusually complex tax code. Developing some law that states tax shelters are only valid if they serve a legitimate economic purpose would be a disaster. This would result in political evaluation of tax shelters by each new administration resulting in large awards over and over again. Many tax shelters used every day by ordinary people result from unintended consequences of the tax law. The best example of this is the 401K. The 401K was the result of some shrewd tax accountant from the Philly area having interpreted the law to allow development of the 401K plan. He tested his idea by forming a plan for a few clients then successfully defended it in court. At some point down the road some equally shrewd IRS lawyer could decide that the 401K is detrimental to the public good because it allows employees to be at risk in the markets where formerly they were shielded by company defined benefit plans. At this point suits could be filed by the IRS to end the 401K and judgments awarded against all of the large mutual fund companies.