The way I see it, it's literally simply the PE paying the existing owner for the privilege of squeezing the value out of the business and its customers in the short term (or in the ideal/theoretical case, running it more sustainably and making higher profits). Management's job becomes to extract high profit in the short term, not to keep the company running profitably.

So, logically, selling to PEs/operators who are known to do this is basically the owners selling out and taking the cash. The consequences are clear to anyone who's been watching.