> Of course having standards is good for patient outcomes. That said, I bet lots and lots (and lots and lots) of the rejected applicants would be fine dentists.
Would you bet your root canal on it?
The fact that there are more people who would like to do something than there are people who are capable of meeting
the performance qualifications for it isn't an inherent problem. Only 0.6% of Navy recruits end up becoming SEALs despite 50% of recruits expressing interest. I'm sure there are many, many Navy sailors who would be fine SEALs, but that's neither here nor there.
Unless you're referencing specific evidence that the qualifications are systematically too strict[0], then it doesn't mean much to say that there are rejected applicants who would be fine dentists. And to be blunt, I think it'd be easier to make the case that they're not strict enough.
[0] The working hours and revenue of dentistry practices are not evidence of this