The standard answer (tipically from faculty) behind this practice is that everyone must know a little bit of science or otherwise that person is an ignorant. There are already a few science books out there meant for future administrators or politicians (for an example, click here).
Here are the problems with that answer:
1) Why is it that not knowing science makes you an ignorant, but not knowing finance, simple business administration, political science, or being monolingual is something acceptable?. I know plenty of science professors that would benefit a lot from some basic organizational skills that anyone could acquire from a few courses in the business school. And what's up with tons of American professors only knowing English? And don't hit me with the purist's view of science being something fundamental, our current modern lifestyle depends as much on scientific/technological developments than on the ability of politicians and administrators to maintain a healthy economy that allows for science funding. Is it arrogance?
2) The idea that people can learn enough science, from a couple of college classes at most, to make "smart" decisions when they are in positions of power is fucking ridiculous. It isn't like 100% of the people that actually finish an undergraduate degree in a scientific field know enough to make those smart decisions.
3) Even if the syllabus of two or so courses were enough for material for someone to acquire significant knowledge of science, it would require great instructors. Unfortunately, Physics would still suffer because the number of good professors in the physics departments's files is quite low. Chemists and biologists wouldn't necessarily do good either, but I think they generally do better than physicists. I once was the TA for a physics course for liberal arts majors at a top research university. The professor was one of the best in the department, at least based on many years of being top rated when teaching physics or engineering majors. The problem was that he lectured the liberal arts majors the exact same way as he'd lecture the science or engineering majors. By the last month of the course, roughly about 60% of the students in the class REALLY hated physics. You could tell they had had it with it. I could only imagine how they would vote on science-related bills if they were ever elected to some kind of office. It really wasn't like they came into the class with a great passion for physics; they weren't excited about it from the get go, but for them to go from being indifferent to hating it cannot be good for the future of science. And I know this was not an isolated event, it happens quite often. And if it happens at the college level, I don't even want to think how bad it could get at the high school level where you might have an unprepared and unmotivated teacher.
I could agree with you if you believe that any person who obtains a bachelor's degree should be a well-rounded person and as such, non-STEM students have to take science courses, as long as you also believe that courses in non-STEM areas are of equal value to STEM students. But, if we really want to do a service to science by educating everyone on it, we better put our greatest effort into the teaching of those courses. We cannot afford to alienate the ones that can end up with the power of funding more science.