I personally love teaching as much as research (teaching as in lecturing, but also as in advising students working on a senior project, training undergraduate researchers, first year grad students, etc), and I see the two as inseparable. There are others who would rather teach than research (although they are a minority in my experience); but yes, the majority of people prefer research to teaching, and see teaching as a chore which only wastes their precious brain time (I could not disagree more with such a position). I wouldn't say it's 99.99% though - maybe closer to 60-70%. I wonder if there have been studies about that.
To those who think teaching is a waste of time that would be better spent on research, and that a "real" researcher is too good for teaching - I always point to this writing by RPF: http://www.pitt.edu/~druzdzel/feynman.html
These are the kinds of things which aren't measured when graduate programs are evaluated, but are super important for people who don't plan to plough into academia, and maybe even more so for those who do!
There's a definitely a lot of opportunity to get non academic career path advice and experience here. A grad student in my lab did a couple of internships at Google during his PhD, which clearly is not something every program/supervisor would be cool with.
As for being unequipped, while in the short term they might lack the experience, over the long run, we're betting that educational depth will operate as leverage, which is why we have education in the first place--so that people can stand on the shoulders of prior giants.
How? That is an assumption, but why to you think it is a good one? That seems to be te question put to you by the PP. It is the micro-analytics of leverage that are in doubt.
However, this has become severely distorted as countries have gone on a major [insert perjorative anatomy] measuring contest to create PhDs, and have pumped effort and money into increasing STEM for its own sake.
IF indeed that is true (I may be being overly cynical), then the "reason why we have education" has shifted from "so people can stand on the shoulders of prior giants" to "because it makes our country look good". How does that affect your analysis?