I think college grads of any field can find jobs, even if they are jobs they don’t like. And there are many ways to make yourself more employable besides returning to school for another degree. You can acquire discrete vocational skills that employers value without doing that. The point of college is learning what you enjoy and are good at, so that you can find interesting work that suits and motivates you.
Not everyone is cut out to be a STEM major, and if everyone were a STEM major, as @apprenticeprof points out, then there would be no competitive advantage to being one. I also know many people with STEM majors/careers who have struggled, been laid off, had to move away from family for short term assignments, whose jobs were replaced by cheaper H1bs, etc. , who lost their jobs when the US gov’t closed the nearby fort or stopped the funding for their research, when AT&T was bought by Lucent, etc. STEM training is great, it’s important and necessary, but it does not guarantee economic security. I live in an area that had Bell Labs, AT&T, Telcordia, Lucent/Alcatel etc. I know from observation that smart, hardworking STEM folks are not immune to job loss and financial insecurity. I know of several American STEM -trained kids who can’t get good jobs because of corporate reliance on cheap foreign H1b workers. The idea that Americans are lazy and won’t do math is not true.