I'm too lazy to look into this, but intuitively it makes sense to me. Healthcare is basically an "exception handler" (default state of humans is to be health), whereas STEM is the "real code".

I would expect more "real code" than "exception handlers".

Also sq. ft. of physical space devoted to healthcare (e.g., hospitals) seems to be far less than sq. ft. of space devoted to STEM (e.g., office parks).

If dig up info to disprove me, I would be very grateful to get a correction to my worldview.