This is just not true.
https://www.irs.gov/pub/irs-drop/n-14-58.pdf
https://www.irs.gov/Businesses/Guidance-for-Examiners-and-Ma...
Just look up "sham transaction" for plenty more. It's a very well established concept and doctrine. Nobody should be splitting hairs about avoiding vs. evading taxes, or generally pontificating about fiduciary duty, without understanding it.
>Actions that are deemed to have been taken solely for their tax effects are clearly and explicitly deemed tax evasion by the IRS
What you said would make almost all tax avoidance into tax evasion. Hell, even claiming deductions would by your logic be tax evasion.
This is just not true.