Why do grad school admissions look at previous employment and how much does it affect entrance into graduate school?

I suppose the question could use some context. I just graduated and I just got a job but I keep getting hounded and getting weird faces from my friends and family because to them a job means no more grad school but I see it as a tool to get into grade school. And it is part of the application grad school to provide previous work history. My reasoning for doing this is because I don't have work history and my academic one didn't end up as good as the requirements were expecting.