> Why should there be a difference in the degree being conferred at all?

You are asking why there "should" be a difference between a CCNA cert and a Computer Science degree. That difference isn't a "should" thing, it's an "is" thing. They are fundamentally different.

> why not split off the departments that confer degrees with a low-earning potential

Earning potential is unrelated to the distinction between trade certification vs academic degrees.