Probably not. A typical fast food restaurant generating several million in sales does mid-six-figures operating profit, with payroll one of the top expenses. Sure, any fast food restaurant could dial up payroll as a % of sales, but not so much that they'd be moving to a different class of employee.
Moreover, the most successful (ie, profitable) fast food restaurants are successful in part because they keep payroll constrained by (a) employing lots of part-time labor and (b) having staffing be elastic with demand. The best workers aren't clamoring to take part-time jobs.
So I think this is one of those sentiments that sounds good on a message board but has no real bearing on reality. But: I welcome a counterargument; I'm no expert, nor would I ever consider franchising a fast food restaurant.
Because $150K+ employees of Google/Microsoft/Facebook/Apple/etc have never been caught being dicknozzles...
Hiring is a probability function. You can optimize it all you want, but sooner or later a complete asshole is going to get through.
The failure of a single employee is not indicative of how well their hiring functions. To make the conclusions you are making, we'd need to know the incidence rate of things like this, but we don't.
There are plenty of better restaurants than Burger King, and at most of them a thing like this would never happen.
Burger King is prioritizing their profit over food safety, but so are the people who eat there. Is anybody really surprised there's food tampering at a fast food restaurant?