Personally, I believe the loss of civics, home ecs, and other courses of that nature is primarily because they are not curricula tied to standardized testing. With No Child Left Behind and more rigorous focus on standardized testing for everything from determining school funding to teacher performance, anything that wasn't STEM or reading has kind of got chucked out the window, and civics/home ec is the easiest candidate since it doesn't really pull any emotional strings like, say, cutting music classes.
When I was a child in the 2000s we literally had two weeks where the "normal" curricula went to the wayside and we did two weeks of test prep for the city and state exams. Then I show up to college and my roommates getting into the top medical schools need to be told how to fry an egg.