I hear what you're saying; when I sat down with Rocky Vista 2 years ago, they had actually suggested I get a biomedical masters before applying to repair my gpa, and as lovely as that is, I feel like the risk of it being a nonsense degree is too high; it costs $30k and does not guarantee employment if med school doesn't come through. That convo was before I took/retook a lot of my pre-reqs (and I also took time off to birth a human.) So yes, my undergrad work is a definite obstacle, however I have 88 credits of post-bacc work with 20+ consecutive A's, and only 2 A-'s, and 2 B's; this was achieved while working full-time (in the medical field) and raising a family. I'm not a traditional student, I'm 33; undergrad grades are a dozen years old. I called Idaho and spoke with them, and the feedback I got was that I would have been a good candidate had I not only scored in 30/32nd percentile on chem/bio, because they were looking for 35th+ percentile. So that is where I shall focus my greatest efforts.
So, anyway, I think in general, yes, additional coursework to demonstrate capability has value, but I'm not sure it's what I would need at this point for my situation.
And if it really came to it, I feel like time and money are better spent on a PA program to demonstrate capability. Because, at least that way, you're still proving that you can handle an intense course load and you could always apply to med school and walk away from PA. But, if med school still doesn't pan out then, you graduate with a pretty decent, usable degree. That biomedical degree just makes me think it's a way for schools to collect more kittens; maybe I'm just paranoid.