> But it's also the case that PE also tends to come in when a company is already troubled in some manner.

The problem is that PE also has a nasty habit of coming into a business that is marginally profitable but not spectacularly so, saddling it with giant amount of debt to vacuum up the cash flow, and killing the business.

There is nothing wrong with a sustainably profitable business. Investors, however, want returns from the lottery ticket that they fund.