I think you give people that spend time learning too much credit; when their actual 'value' might be quite marginal. As a working engineer, I am that person you talk about, spending lots of time gaining knowledge and understanding how things works, and making products for customers. However, I am not so high strung to see my knowledge as some type of entitlement. or my abilities as more valuable than next person's. I am only as good as my last project. I have had to knock a few other engineers and scientists dicks in the dirt because they walk around thinking they are some type of savior to the world. I think this comes from society's lust to worship at the religion of science.
I read an interview with Mike Rowe, and he said something to the effect of he has met more millionaires covered in crap than he could have ever imagined. I think people like this are going to be highly valuable as we move into the future because everybody wants some type of while-collar job, and people that get their hands dirty or have real skills making stuff with be in low supply. People in the sciences will always be in high demand, because it requires hard math and more perseverance than most people care to conjure up. It is the people in the middle, the ones with soft degrees (business, psychology, law, etc.), that should probably be shaking in their boots. Those people, unfortunately I would argue, are over rewarded for pushing paper rather than actually getting something accomplished at the end of the day. Not to say they are any less valuable, but over rewarded for what makes 'all boats rise' in society.
The best piece of knowledge I ever got out of school was from my material professor. On a night when we were in the shop learning how to mill things, he turned around, and told us pointblank: When a machinist tells you 'that can't be made' you need to shut-up and listen. Because you can draw whatever you want in a CAD program, but these guys are actually making things out of real materials, and you need to understand what they are telling you.
That has stuck with me since that class in '95, and I have had to tell that story to so many engineers because they just don't get it. We still get Solidworks models that have issues once it hits the floor of the fab even with all the CNC and laser cutting equipment, and for all the optical path modeling software, reality of laser power coming out the other end and spot size is such a gross error, I do question the need for the modeling step. This is a can of worms, I will just let it rest for now; just don't go there.
I think the part you missed is this. Sure someone doesn't have to be super skilled to be a dog walker. But if you a hundred people posting that they will walk dogs, and only one person with blueprint making skills, how many hours do you think each person would have in their timebank buckets at the end of the day? I would guess, the engineer would have 7 hours available to get other work done that he needs; while one person would have an hour for walking the engineer's dog, and 99 others would still have zero. Those 99 people would start to expand their skill set.
If life was purely cerebral, then the engineer would win hands-down; but it isn't, and I can see a lot of value in people doing what others might consider mundane, brain-dead work.