Interestingly it's the same with attribution requirements for art, but since it's not written words, nobody can claim: "this part is exactly my GPL code". But with art it's "this is exactly how I do texture on metal", "this is exactly how I paint steampunk greeble", "this is how I do clouds" etc.

I'm glad you're responding with real issues, though let me reiterate that my comment was more to amuse and vent.

Long live clopen source!

> Also, discriminating like you suggest would make those licenses closed source by definition.

Definitions are not what matters in the end. Why doesn't the viral and restrictive element of GNU's GPL license make the license "non-open"?

Definitions are what matter, they're the reason you can use words and I can understand what you mean by them.

"Open source" has a definition (https://opensource.org/osd) and the GPL meets it, because it doesn't prevent derived worries from being distributed under the same license.