When it comes to actual recipes, I find that most things I like come from a lot of repetition to adjust the details and figure out the pitfalls, so even if it's generally similar to what was published, a lot of value has been added from my perspective.

Code can be written deliberately in a kind of unfinished, unrefined way, and let those who would use it go through a similar process.

But the GPL seems significantly different from the absence of copyright.