I think sometimes the proof can be visible in daylight, but you just need to take a deeper look to see it. Certainly if you take the view that "if you are good enough, you will get the job" why is it that we continually see the same cycle of managers at the lower end of the Premier League, who all achieve the same average or below average results, play dinosaur football and inevitably get sacked before getting another job at the same level a while later? I'm talking your Allardyce's, Hodgson's, Moyes', Pardew's, Warnock's, etc. Do you really think deep down there are no younger talented managers below these people who have enough ability/ambition to get through to the top?
Why is that Stevie's first gig is at Rangers, or that Lampard is now at Chelsea having taken Derby from 6th to 6th in the Championship, yet I have never seen an elite black ex-player manage a top club in my lifetime? Is it that they just don't want to go into management generally, or is there something clearly more to it?
It's a similar case with referees as well. Whilst there is some club bias involved, it is widely agreed across fanbases that the standard of refereeing at the elite level in this country is abysmal. Yet again though, we just see the same faces over and over. Is the pool of officiating so thin that this is truly the best we can find?