Not so much virtuous as respectable - desirable even. It’s important to me that you hold down a job (if you’re fit to), and it doesn’t matter which job. It indicates reliability, self-sufficiency, a level of commitment. And it’s fairly simple really: you turn up on time; you actually do the work; you get paid. What annoys the hell out of me is getting paid shit money for doing your job, but that’s a whole other answer.