The general rule of thumb with PE(not so true maybe in the last 2-3 years) is that if PE starts showing up en masse to your industry your industry is either half alive and needs an emergency operation that might kill it or it has a lot of excess fat that is obvious by looking at the balance sheet.

Not one of the ones he listed (retail, healthcare, defense) are industries where people would look and say "this is working well, fuck PE for fucking it up".

Tech and software buyouts by PE only really started happening within the last 5 years, so can't make a judgement on that yet.