A bit provocatively titled, as I can only imagine doing something like medicine "for the money" is a recipe for misery. Also, who are these people who are debating between careers in finance, law, or business over medicine? I have never considered those first three and could not be happy in those settings, but that's just me.
That said, I agree with your conclusions Dbate, but a few thoughts (not directed at you but in general):
Regardless of compensation, medicine offers to the most secure future in terms of choosing where you want to live and hours you want to work of all higher-paying professions (depending on specialty, though. Nuclear medicine probably isn't one of those specialties if I learned anything from the recent 20 questions, but primary care and psych probably are). The "floor" of compensation is relatively very high in medicine (ie, the vast majority of physicians, even those in the lower 10th percentile of those who work full-time, still make a very good amount). Obviously this is not true with lawyers, who, on average, make a similar amount to nurses. If you consider T14 grads as a more comparable population, I would still argue that physicians have greater personal autonomy in terms of employment options whereas a T14 grad would be more at the whim of who offers them an attractive salary and the initial workload that entails. With finance, I could only imagine that personal autonomy is impossible in those regards.
So for that mythical person who is debating between those high level careers, I would agree that medicine is the best choice not only from a financial perspective but from a perspective of autonomy over your life as well (once training ends anyway).
Edit - Obviously crazy amounts of educational debt, which are becoming extremely common for medical students and will continue to become even more prevalent in the near future, throws the equation, especially if you compare it to finance out of undergrad with no debt.