I think there must have been a period when a lot of people did PhDs - like a fad or something, because my parents know a lot of people their age that had career breaks and went and did PhDs and 90% of those people didn't get it finished, and just went on to other things, so maybe there is a generation of people who have seen a lot of people never complete?
I can't stand it when my parents give me advice about my PhD, they haven't even got degrees and they phone up and say "you should do your writing on the train" - and when I point out that I need a PC, endnote, hard copies of journals, internet access etc. to do writing, they just say "oh stop making excuses"! - like writing a thesis is like knitting or something, you can do it in your spare 5 mins throughout the day! GRRR.