The thing is, there are few industries that are as cut-throat as fast food. Wherever franchisees see an opportunity to save even a couple dozen bucks, they will take it, laws don't matter.

And enforcement is pretty lacking in itself. Most people won't report it to the authorities that they got the runs from some ice cream, the authorities will only hear about it when dozens of people arrive at the hospital with the same symptoms, and even then most public health departments have already been understaffed prior to COVID to follow up on the hospital reports and conduct inspections.

What McD/Taylor are doing here is, as fucked up as it is, the only meaningful way they can make sure they're not labeled a public health risk.

And yet you don't see Wendy's frosties killing people all the time? Are their machines magic or is following a "take everything apart, soak it in this sanitizing liquid, rinse it, put it back together" not actually hard for a kid who has been trained and given ample time to do the task? Also I'm not convinced most fast food employees are kids anymore. Plenty employees are well into adulthood.

"Qualified" person is not somebody who had evening school, and can hold screwdriver.

There is a chain of custody, paper trail, spare parts certification, logging... For example if there is a heat ex-changer that sometimes does not work, it may cause a lawsuit. McDonald (and insurance companies) wants to be able to sue ice cream machine manufacturer.

I also want to be able to replace any "suitable" parts in my car, but sadly government does not allow that! Remember, when everyone lost their shit with Volkswagen "cheating" in their software?

Managers themselves used to receive training for basic maint on the older machines before the automated sanitization cycle.