"Security-minded" folk who insist corporates should have full control of their device via signed code from pre-boot, incidentally preventing "non-authorised" replacement parts from working since repair is an attack vector, allegedly.
Maybe sabotage from competing farmers? But that seems far less likely than the owner wanting to maintain his equipment after the manufacturer has abandoned it.
Remember, doesn't have to be likely, just has to be a good headline.
Edit: Replied to the wrong comment...
Which means bringing it to repair shop.... which means evil maid or whatever mix of flavor of vulns that creates