Disapointedone, I am head of HR in a biggish organisation. I left school at 15 with no qualifications. Yes it can be done, damn easier 40 years ago than now. At 21 I was buying my second house, 2nd baby so we decided we wanted something bigger. By 25 I was studying part-time.
I wouldn't advise my kids to do the same.
My DD is mid 20s. She has a first class degree from a top ranked uni. She has travelled the world, some of her travel was free as she was on uni projects where she got paid pocketmoney plus expenses. She has a good job. She has plenty of time for the mortgage and babies. She has her degree, she has her post grad qualifications, she has a fantastic CV. For her current job and the one she is soon starting she applied on line and in minutes, yes under 15 minutes, she got phone calls from the companies concerned and in the first one within 30 mins they had applied for her references. In both cases they said her CV was fantastic, the breadth of experience for her age was outstanding. She has lots of work experience starting at 15, all her jobs were something she could link to her ambitions, she had two career plans at that age and even the job she did at 15 is relevant to the career she has chosen. Even without her job I don't think her degree is a waste, a degree shouldn't just be about how much you earn and for her it was much more.
In my 60s I can see there is time to do lots of thing but at 18 I wanted the house the babies the job.
I did my part-time studying for 5 years and yes I did OK but I didn't have the fun she had.
Did I do it wrong? Maybe, it has turned out well but it was hard work. Did she get it right? I think she probably made better choices than I did but who knows how her story will end. The point is there is more than one path and your path might have been a good choice for you or there might have been a better one, who knows?
I hope you didn't turn down a good candidate because they had a PhD, they might have had lots of other skills, don't let prejudice blind you. It diminishes you because as someone said it makes you look as if you have a chip on your shoulder which is never a good look.