A little unrelated to this whole thing, which does hit me a bit personally since my cousin back in Iowa died of opioid-related dependency issues, but I have interviewed a lot of consultants over the years for various roles and they are without question the most consistently bad interviews. It's funny, when I was in business school years ago (please forgive me) getting a job at McKinsey or BCG was more or less the crè…
I've also interviewed many consultants over the years. It strongly depends on what you are interviewing them for . If you want people with deep industry expertise and a strong fit for a fairly narrow role, then yes of course the consulting kids are going to suck. If you want people who can learn quickly and look more broadly than a specific department to do things like strategic or financial planning then consultants…
I don't think strategy advice is worth much unless it's coming from people who stuck around and lived with the consequences (i.e, tested their ideas against reality).