Katnina,
With all due respect, most of us made the decision to become physicians when we were about 18-20 years old--the idea of FIRE was nowhere on my radar.
In order to get accepted to medical school, we busted our butts in undergrad, studied like crazy, and jumped through a whole lot of hoops. I can't speak for the rest of the physicians here, but I worked my ass off to "take a degree spot from others".
Once accepted to medical school, there were the four years of study, three of which were unlike anything else I'd ever experienced before (I'll admit, fourth year was pretty nice). I studied a lot to get through organic chemistry, but holy crap, I'd never been in a situation where my notes for one test created a pile five inches high. And that was for one test out of three or four for the week. In addition to the innumerable hours, I spent about $65,000 in tuition for the privilege of having taxpayers subsidize my busting my ass.
During residency, as noted above by Hamster, we worked very hard to take care of our patients (residents do a huge percentage of the patient care at academic medical centers). When I was in residency, 80-120 hour weeks were common during ward months.
After many years (12, in my case, from undergrad to finishing residency), we are finally free to start practicing medicine. Well, as it turns out, practicing medicine kind of sucks. Sure, I'd love to have known that before I spent 12 years of my life working my ass off to get here, but it's pretty damn hard to know what it's actually like to practice medicine until you actually get there.
Most of the doctors I know feel the same way I do. Given the percentage of physicians who are unhappy with medicine, I think it's safe to say that those people we "took spots from" wouldn't be shining beacons of benevolence, but would be just as unhappy as we are.
So, yeah, I'm aiming for FIRE. I went into medicine to make a difference, and my patients tell me that I do. But it's not enough. I like taking care of patients, but the constant threat of litigation and the ever increasing amount of interference (both administration and governmental) make it a very unpleasant job. Given that I invested a WHOLE lot more of my time, sweat, tears, money, and life in my education and training than "the taxpayers" did, I don't really care what they think about my goal to FIRE.
For what it's worth, I know two physicians who went into medicine for the money/prestige. Interestingly, they're pretty happy with their careers. It's the ones of us who wanted to make a difference who aren't happy.