I agree, and neither is a PhD, but I don't think that's a great reason.
"Why don't we pay teachers a decent wage? Because money isn't everything and helping students grow to the next generation is something that is inspiring in itself."
It's easy to say "money isn't everything" when you don't have to worry about money. A single parent is unlikely to be able to quit a decent-paying job to work with the low wages of a PhD program; are we just going to say "single parents need not apply" or "your kid should learn that money isn't everything while you live on subsistence wages for the next six years"?
Obviously there are single parents who manage to their PhDs, and that's really cool, but I don't think it's realistic for a lot of (otherwise qualified) people.
Indeed, the GP admitted it's an "indulgence", i.e., a luxury to be able to pursue a PhD for the love of the process. I don't think it's realistic for many people, particularly a single parent, nor necessary to have a fulfilling career that makes significant academic contributions.
I think this is a false dichotomy even though it fits in with the traditional American template.
"Go work in industry after undergrad/masters" or "forgo making money to pursue a PhD".
Maybe it's borne from the bubble of academia, but as I got more experience in industry it became apparent there were many, many more pathways to a PhD than were discussed while in university.
