For an engineer, MBA is just a natural progression to what is perceived necessary to become a manager. Medical school would be an extremely time- and money-consuming career change, so I don't see why any of this is considered any surprise. Med school attracts a different kind of mind than engineering, and it's only a common thing to combine with engineering when you're specifically studying biomedical engineering. Quite a few chem eng's are interested in this (not me) and they go on to medical school after their BS.
Although nursing is supposedly in demand right now, this is a truly horrible job unless you have either really strong interest in helping people, or are doing it solely for money. Long hours, exposed to sick people and probably all sorts of things in your worst nightmares, and then only a minimal level of career prestige and low pay compared to doctors, it's no wonder so few people choose this. My friend's mother is a senior level dialysis nurse, she makes decent pay but the job sounds terrible, and she works 80 hour weeks.
At least until our economy really collapses, I think the best way to go is trades - car mechanic, plumber, construction, electrician. And I think these only require simple maybe 2-year certification programs, and a high school diploma, and it's simple to have your own small business.
