From personal anecdote, well two points.
(1) I know quite a number of literature Ph.D.s who have good and happy lives, some as professors, other doing other things.
(2) I myself have a doctorate in post-structuralist political philosophy. Not really a field better suited to actually getting an academic job than literature is, if you look at it. It's true, for a number of years I had a somewhat distorted notion of my odds of getting a tenure track position doing that. I didn't. And now I get paid quite a lot as a consultant to a computational biology lab that has built the world's fastest supercomputer (at least fastest, by orders of magnitude, for doing molecular dynamics). I'm happy... and specifically, I think doing my humanities doctorate was absolutely delightful, and some of the most fun I've had in my life.
FWIW, I don't have 'Ph.D.' next to my name out of a financial motive. Quite possibly, if I had spent an extra decade slinging code, I might have more money saved (I'm old too, by slashdot standards, late 40s). On the other hand, I probably wouldn't be making more as an actual rate, and specifically those little letters--even when they are in an unrelated field--actually do help my resume/CV float to the top next to ones that lack them. But indeed, money isn't the question for my life--I've done things that are fascinating and rewarding to me instead, and am pleased with the outcomes so far.