And also, perhaps transformed the company ownership structure into a limited partnership as well, claiming a lower market value for the shares owned by limited partners.
tl;dr: First rule of US estate planning: Die broke.
Look up "family limited partnership" or see:
http://scholarship.law.marquette.edu/cgi/viewcontent.cgi?art...
https://www.forbes.com/sites/brianluster/2014/03/18/why-form...
Note especially the discount from fair market value for shares of interest in an FLP.
[usual disclaimers - not a lawyer, not legal advice, see a qualified professional in your jurisdiction, etc.]
The problem with tax/estate planning is the same problem as insurance - the time when you really want to have done it is often the time when it is too late to get it. (e.g., founder/owner is dying, building is flooding or on fire, etc.).
Also, laws change all of the time. My impression, every time I dig down with real people, IRL, is they have the same general opinion as you and others like you here, but have no actual exposure to the actual laws, as they implemented. The only occasion I come across this and I see that the business owner, with a small team tax attorneys and CPAs, can't seem to spend enough money to escape huge taxes.
I can only assume that the business owner is clueless and the Internet anons are the experts he should have hired.
Unfortunately, the way tax laws are applied usually makes it impossible to apply in retrospect - you have to build it into the business structure from before day 1; and often the non-monetary cost is prohibitive -- e.g., you can reduce your tax burden by 70% by moving to a different state / country.
As a successful business owner, tax is going to be one of your largest expenses. Makes sense to a major optimization target.
His issue was that what the government decided his business to be worth could only be paid with more cash than his business generated in 5 years. This meant that his heirs would have to mortgage their shares to cover the inheritance tax, which places ownership into a different category of investment.