Although I agree with some of your latter points (and I am not trying to start a debate), your first sentence came off to me that you are frustrated that students with minimum pre-reqs scrape by to get in while you have more biology classes. So I'd ask the same question in reverse, why would someone in my position make me a lesser candidate?
While working a 50 hour/week job, I pursued night courses every night for 2 years and not only achieved A's, but maintained to be at the top 3 people in each course. In addition, I studied for an entrance exam that comprised of material from completely different subjects than my undergrad degree (of which I only had the bare minimum) and achieved 21-24 for each section (less 1 section). In addition, I exhausted my vacation days to shadow and volunteer to keep up with traditional students.
If you were in my shoes and found out that you wanted to pursue dentistry later in life, would you want them to require 45+ hours of biology you didn't have? They have requirements, and I've met them. I also have an undergraduate degree and maintained a high GPA. I've proven my determination for dental school. I'm not a genius by any means, but I've worked hard to achieve where I'm at now. If schools need to determine my character, then that should be where the interview comes in.
Just my $0.02. BTW, if I came off in my previous post that older applicants are better candidates, that was not my intent. I was just posing a thought that perhaps that's why I haven't heard back because I know some schools such as Baylor bring in non-traditionals at the same time on a later date and wanted some opinions.