Honest question: why is it terrible? I would assume that if someone is capable enough to struggle for 2 years, they stand a real chance to struggle for 4 years

Honest question: why is it terrible? I would assume that if someone is capable enough to struggle for 2 years, they stand a real chance to struggle for 4 years and graduate. And seeing how the job market rewards a mediocre diploma from a good college significantly more than a good diploma from a mediocre college, it seems like a very rational decision from the student's side. And if they do fail out, they should still be able to enroll in another program, and presumably get a decent grade there, no?