This is true, I didn't mean to suggest there weren't good exceptions. Although instead of starting from scratch sometimes reassigning crew will uncover unknown strengths and weaknesses.

Personal example of this, an old foreman I knew on a job, had a boss who didn't understand that people had strengths, so as an example he would routinely swap people into tasks that emphasized their weakness to prove it.

Additionally, this allowed people who didnt do X job because they didn't have the confidence or skill, to actually get a little extra experience as well