I remember an assist. principle getting the nod for principle. Not because he was qualified but because he was one of us. This is rapid thru everything. A gentleman complained once to the mayor about someone who was brought in for a job. The complaint said "and he is not even one of us". If you refuse to listen to criticisms then you are refusing to grow.
The problem with these anecdotes is they can be made up to suit a person's agenda. Nepotism and favoritism, or what you call inbreeding, go on all over the country, unions come to mind for one thing, and we all have our stories of jobs lost and promotions denied because of it. Who are the ones you call qualified and "not one of us" that we should be seeking for their "criticisms"?