College might not guarantee a job, but how much harder is it for those applying for jobs where a college degree is a prerequisite?
You have just made the "A college degree is not a guarantee of competence, it is a union card substitute". argument. If you don't value your degree more than that, it says a lot about how much effort you put into actually learning from your courses, and it begs the question of why I should value your degree more than that, as well.
Actually, it's more of a signaling argument where a college degree indicates a willingness to put in effort and learn and thus will probably apply those characteristics in the job. It's not a perfect signal as there are plenty of educated derelicts and smart, talent people without a degree but as a first cut it is easy and thus used.