This debate is entirely concerning G-reg planes - being self fly hire of planes from flying schools or clubs.
It's fun to reflect that if this debate was concerning N-reg planes, we would be looking at an immediate ban on all flights. The CAA/DfT would love nothing more than evidence of poor maintenance on these. They are really scraping out the barrel to find some, without success.
But, the condition of the G-reg fleet will always be acceptable to the CAA because the CAA gets a nice bit of money out of it: CofA fees, and money from the firms that maintain them.
They get even more from some operators, in the AOC fees. A firm that has an AOC has to do something really dreadful to get prosecuted for anything.
Call me cynical...