You'd think that people would go into finance or get an MBA if they only wanted money. Everything that I've seen has indicated to me that, next to being an active-duty soldier, a life as a doctor is probably the hardest profession. Given, there are certainly specialties where this doesn't hold. Still, I have no idea why people choose medicine if they aren't prepared to make those sacrifices.
The average person in finance/business doesn't actually make that much money, can get fired/laid off fairly easily, has a job that may very well get outsourced/downsized, doesn't have as
inherently altruistic of a job (any job that supports your family, without being at the expense of others, is altruistic in my mind), etc. etc.
Medicine is one of the few things that guarantees a six-figure income, as well as job for life (assuming you aren't grossly incompetent, and
even then it's sadly hard to get fired or not find another job somewhere). The odds of the average physician having to tell their spouse they were laid off are almost nil. If it happens, it's likely because the hospital itself closed, in which case it will be very easy to find a job
somewhere. Few professions can guarantee all that--much less a career you can be proud of.
Still, going into medicine for the money, as you and others point out, is a terrible, terrible idea. Burnout is high enough in physicians who truly want to serve and help others. The money and job stability are just good things to remind ourselves of when we start complaining about our loans, time in training, etc.
The pay is not at all worth all the time/education/sacrificed youth/stress over $300k+ debt/etc. But the joy and meaning I get from being a physician certainly are.
Still, watching my other colleagues makes me really thankful I chose PM&R. (My alternative was psych, which is arguably the easiest specialty to have a great lifestyle in). But my friend in neurosurgery would shoot herself in the foot if she had to do what I do, which is why I tell people to do what love/enjoy/find fulfilling.