IF you try to understand it from the regulators perspective, it totally makes sense. You see, the law is written for legibility, not for variation, and rightly so. $15k cash in the bank is easier to understand than $300k in ETFs. Your $300k ETF might be stable or it might fall below the value of $15k over 6 months (not likely but government officials are not in the business of investigating the stability of individual ETFs). An old HN comment about makes this point about “legibility” well:

“To the state, one of the most important goals is legibility. The state has an enormous burden of regulation in its various enterprises, and the less variance the easier the job. This certainly isn’t ideal in many, many cases, but in this case a person who likely didn’t make the standards quite rationally trusts a vetted standard over one small trivial test given to them by a company they’re evaluating. FIPs standards are probably much more exhaustive than just a hashing performance test on one piece of hardware.”

https://news.ycombinator.com/item?id=25543818