Nobadwords,
The better question might be thus: Why stick with what you *thought* you wanted to do your first year in college, when you later realized there were better possibilities available to you?
I planned on going to med school (like my dad!) but then realized there were better options for me. Those options included business school, law school, getting a masters in adult education, and dental school! I would be stupid if I stuck with med school after recognizing better potential (for me) in other career fields. By the way, potential has nothing to do with MCAT/DAT scores or GPA.
Do you realize that psychiatrists don't deal with patients who have cardiovascular problems? Do you understand that an opthamologist won't remove a patient's ruptured spleen? Both of these specialists are MDs, yet they treat only a specific function of the body. Hence the term, specialist. You seem to think that MDs treat everything and anything, which isn't true. Specialists are only a part of a complete medical team. I'm sure glad there are doctors available who are specially trained to work with teeth and structures above the neck!
In the same way that a psychiatrist or opthamologist must understand the entire physiological system, so must a dentist. I'm sure that when my future patients come in for cavity treatments, they will appreciate the fact that I understand how their oral health relates to their entire body.
Afterall, if my patient is taking Calan (a calcium channel blocker used for mild hypertension) then I had better know what amount of anesthesia containing epinephrine I can use.
The term "doctor" doesn't mean much to me. I don't place my worth in a title. A piece of advice for you in case you aren't familiar with the legal system: people can be stripped of titles, but not of knowledge. I'm in it for the knowledge, how 'bout you?