Except that the usual thing is to pay the new guy more and believe his story that the tech he used at the last gig, that he is now an expert in, is better than how you did it. Now management makes the new expert the boss. Next thing the old guy discovers the new guy was just in the right place at the right time in the last place and is useless, but, because he is the new boss you have to do everything again.
Fair point. That would definitely be a bad scenario as well, but would imho be a different issue from hiring someone from outside all together. A bad hire is a bad hire, and someone who comes in wanting to change everything to fit their way (especially if their way is wrong) is not a good thing. I still don't know if the original point is accurate as a common mistake, and perhaps the bigger issue would be that non-technical people make bad choices when trying to find technical leadership that are the wrong fit?
I agree, both reasons. The funny thing about this, in a dark funny way, is, management often offers a veto right to the team. They say "if you don't rate the new manager you can deny". Then, they hire anyway, in my experience, more often than not if they like the guy. I think the excuse is "You people doing the work (often with 'in the trenches') don't understand the big picture, this new guy does, so your veto is annulled".