It's not self-justifying sophistry. Most things (including software) get invented independently multiple times. I've done it myself. Independent invention invalidates any moral claims to "intellectual property". The massive costs to society mean that we all have to (reluctantly) acknowledge that an "ownership of ideas" can't really be enforced practically. Enforcement of ownership of ideas would entail no civil liberty at all.
I don't write software for a living right now, but I have in the past. Go right ahead and take a look: http://stratigery.com/source.html Take a copy, too. On the house.
You're confusing copyrights and patents. I agree that nobody should be able to own an idea, at least in software, but suggesting that nobody can own an implementation is naive anarchism.
OK, I'll bite. How can I tell if I've re-invented your (wholly-owned) implementation? If I actually come up with a way to do some particular task without consulting php.net (or whatever) what's to keep me from (very inadvertently) "stealing" your implementation?
I'll give you an example: a while back I wrote some code in C, to push an element on to a linked list. I forget exactly why, but I ended up passing the head of the linked list as a "struct list " or something like that. That project died, but I kept the function just because I was so proud of it.
Years later, I saw a programming quiz. The question was almost exactly my task. The answer to the question was my function, with the variables renamed.
Independent invention. It ruins "Intellectual Property" as property.
And yes, I'm deliberating conflating copyright and patents, because the rest of the world does so. It's "World Intellectual Property Organization", not dual "World Patent Property Organization" and "World Copyright Property Organization".
I don't write software for a living right now, but I have in the past. Go right ahead and take a look: http://stratigery.com/source.html Take a copy, too. On the house.