First, as others have pointed out, you need a college degree to get serious gainful employment (if you're lucky). But let's leave that aside for now and look at the big picture. This isn't about me or any particular person, it's the fact that the US welfare state for example (GI Bill, secure employment, everything that created a strong middle class) was undermined since the 1970s thanks to neoliberal policies of privatization and deregulation. In order to continue sustaining mass consumption, loan markets and debt were expanded. You can read Paul Pierson, Wolfgang Streeck, and a number of other political economists who have done serious research on this issue. I'm sure if someone did (probably has done) a historical study of average proportion of household debt it's increased significantly across the board since then, and not just because of educational expenses alone.
The banks and other financial institutions further created markets to trade these debts including creation of Collateralized Debt Obligations, debt swaps, and other financial instruments. Speculation eventually led to the most recent economic crisis of 2008, which of course completely screwed the employment situation for tens if not hundreds of thousands of recent graduates who just happened to be born at the wrong time. So it's not hard to see how these policies and decisions have accumulated over time to force us into the current dire state. Whether someone picks a STEM major or not then is irrelevant to the larger system and its impact on the whole generation.
I mean seriously, forget degree for a minute, you wouldn't tell people in the Great Depression to buck up and go sell their wheat at the next town's market "because man you'd totally be doing better off if you made the right choice." Such moralizing is useless and only obscures the real issues.