It's up to them to decide. I, for one, have seen far too many people go the route of academia, stick to it, and then regret it because they either didn't get a tenure track position, or because they were so old when they got one.
It depends on the discipline. Engineering/CS is soft on academics. When I was doing my PhD, it was not unusual for a graduate to get a TT position without doing a postdoc. But if you're in the sciences or math: Good luck.
You are responsible for taking care of your needs. If all you care about is research, and not enough money to pay for your kids' college (the situation of a number of career post docs I know), then I'm the last one to tell you to reconsider.
This is why a system that fails to associate value added with reward gained is so utterly damaging.
If salary were a function of social value added why is the Pepsi CEO so well paid? So many industries just appropriate wealth from real work.
If people don't yield to the flawed system I say hats off to them.