Just because you and I can trust someone to use corporate funds wisely is no reason to legitimize what would be illegitimate use of corporate funds. Yes, we know we could trust Elon to not use corporate funds to buy a yacht for personal use but that doesn't mean he should be granted contractual permission for things that would obviously be illegitimate use of corporate funds.
In fact, the Board doesn't have the legal authority to do that, it would be illegal.
I disagreed because you have posted completely incorrect information. Corporate compensation practices vary widely and often consider tax implication in compensation choices. To my knowledge some such seemingly bizarre choices as these exist for sound reasons:
1. Unlimited First class air travel for employee, spouse and dependents;
2. Unlimited personal use of corporate aircraft fro employee and family;
(Those two are not at all uncommon, usually for security reasons, but not exclusively so)
3. Company pay for all alcoholic beverages use in company-paid housing which also includes every single expense associated with the residence in question.
4. Providing company owned yacht for any purpose chose by employee.
5. this ignores some such benefits for lifetime upon retirement.
The list goes on. All these benefits and others like them can easily be described as profligate and outrageous. All of them are sometimes prudent choices. Some of us posting here have been beneficiaries of some of these benefits. Nearly all of us are likely to think they were either cheaper or less risky than would be alternatives. Some of those also are explicitly tax beneficial ways to provide compensation.
Obviously, you might want to think about what ids and is not "illegitimate" and why.
In conclusion, without a doubt it is common to abuse such benefits and/or use them in unwise ways.
Were such to be extended to Mr. Musk it would not necessarily be unwise, but I doubt he'd have the slightest interest in a yacht. I know of one such case in which the yacht in question (a really huge one >50 meters) is profit making for the corporate owner. If I know of one, surely there must be quite a few in similar financial status.