My dad owns a small construction company, and I grew up working for him, and on my grandfather's farm. I've framed houses, poured and finished concrete, built masonry walls, installed plumbing and sewer systems; the list goes on. I have a dual major in architectural engineering and construction management, with a specialty in designing mechanical systems; including plumbing and HVAC systems. I've installed them, and know how they operate. I've put my time in many times in the field, and I feel I've got a good grasp of what goes on in the field. I'm on all of my jobsites several times a week to answer any questions with my crew, and to help come up with solutions with any problems.
And also, if you think all of us engineers are nerds, and simply live in our offices; well I played football in college too and had a pretty good run at that as well. Before you go spouting off about engineers, try to think about the amount of hours we put in trying to design a certain item, under tight deadlines, all the while trying to appease the owner asking for the product. Like I said, a lot of the times the product is determined by what someone wants to pay for it, and the criteria for the design.
