That isn't a fair characterization of me, or my motivation for getting into medicine, and this post has some very naive things in it.
First, I've never said that you can't just go straight into medicine. However, if you are intent on going straight into medicine you are going to be competing against many fairly indistinguishable people and it is going to take an incredible amount of arbitrary effort to stand out. If you are fine playing that game then by all means play it.
What I said originally, and stand by, is that you really have more time than you think and so long as you are pursuing real experience and challenge, you really are only going to improve your application when you do decide to pursue medical school.
Also, your last point about being a "jaded Marine vet" is just ridiculous. Being able to comport one's self under stress is a virture. It's one if the reasons why these schools want clinical exposure and why they ask you questions about it. Its also why they often times blatantly ask "how do you deal with stress."
Edit: also I think we would all want to go to residency as well prepared as we can be. I'm not interested in making mistakes with actual people, and I've learned from experience that we are at our most dangerous when we start to think we know what's going on. I'm way more interested in not screwing things up than I am living in my own version of Scrubs.