Man, this view of getting a PhD, which seems fairly common, is so alien to me. Both my parents are research professors, both regularly have students, and I have never seen any of the misery or stress that people keep bringing up.
Sure, if you are unprepared to do research then you shouldn't do a PhD, but my parents' students are hand picked, and it is very rare that they end up with a student that doesn't want to, or is unprepared to do research.
Being a PhD student should be one of the most fun parts of an academic career. You get to focus on your research, and are mostly removed from the politics and stress of securing funding. You aren't constantly being barraged by requests to review papers or having your time used up by a myriad of other responsibilities.
I guess it is totally possible that the corner of academia that I grew up around (ocean sciences at a lab removed from the main campus) is an outlier, but my impressions of getting a PhD were always positive, and the reason I never did it was because the part after your PhD seemed like it sucked.