On the other hand, open source culture is vastly different from proprietary culture.

So many times in proprietary culture I've churned out craptastic code to meet a deadline that didn't matter for a project whose customers were straw-persons. There's definitely some projects or features I've coded which I'm glad to hide from public view.

That said, artists can curate their portfolio, and unless they're presenting to a public forum, their turds won't have to see the light of day again.