I think most people (namely high school seniors) go to college for neither. They go because that was the expectation, and was assumed to be at least approximately productive path.

While arguably that's indirectly 'for the piece of paper', I'd argue the pleasant experience is a factor too, even if not quoted as such. i.e. if it was a purely rational, economic choice (my interpretation of going to college just for the degree) we'd see higher enrollment in high-ROI majors.