> GPL is unethical

No. You think that GPL is unethical. It does not make it unethical.

After thorough reading, your blog post did not convince me and here is why:

> Proponents argue that the GPL has a long-term goal of making more software free for all, by limiting short-term freedoms of some, for the sake of encouraging the propagation of the GPL via software, like a virus. That’s why it’s called a viral license.

This is a faulty comparison [1]. You do choose to use a code under GPL and make your code under GPL as a result. You don't choose to catch a virus. See also [2].

> they are using a system they fundamentally disagree with, in order to promote and propagate a new system, and they are doing this from within the new system, which they would replace the old system with from without if they could.

What is your suggestion? They live in our world by its rules. How do you want them to achieve their goal?
Also, what is wrong with doing this?

> So the authors of software have rights, a fact which proponents of the GPL agree with. But they argue that the users of software have rights which should, in an ideal system, trump those of software authors.

> This is a clear contradiction. In an ideal legal system, either the software authors should have the absolute right of licensing their software as they see fit, or the software users should have the absolute right of accessing and modifying the software regardless of the software author’s wishes and intent.

Sorry, I don't understand the contradiction here.

> Experience shows that most people see nothing wrong with the current system: let authors distribute their work with whatever licenses they want, and let the market decide whether an author’s requirements are reasonable enough to cooperate with.

Great. If "experience shows", you must have a reference, right?
Anyway, this is an argumentum ad populum [3]. "[it] is a fallacious argument that concludes that a proposition must be true because many or most people believe it" [which does not make it right].

Also, I don't want to "let the market decide". I want good behavior to be enforced, not some hazardous process that might end up producing a good behavior. The "market" is not necessarily right. There is no guarantee here. But I agree this is personal opinion.
Anyway: choosing to use GPL is indeed a way to participate in this free market, if such a thing exists, and "let it decide".

> Practical philosophical systems agree with this. When someone creates a work, they have the absolute right to do what they want with it, as long as they themselves do not break the law, and as long as the existence of the thing itself doesn’t violate the law either.

Oh, there we seem to agree. So authors of GPL software do not want to see their code used in proprietary software.

> Thus, the heart of the GPL goes against common sense, experience, and the just liberty of creators over their creations.

It goes against your common sense, not mine.
Talk about common sense now.

> But that actually brings up an interesting point: the GPL actually limits people’s freedom.

This is the point of the GPL. To prevent people from reusing the code without forwarding freedom to users.
If you make a code that is proprietary, you are the one who is "actually" limiting freedom of other people.

One person's freedom ends where another person's freedom begins. Freedom is nothing like an absolute graal.

If you are pissed off because you can't reuse some interesting GPL code in your proprietary software or your permissively licensed software, well, you are free to not use it. Nobody forces you to do it. You are also free to (re)consider setting your program under GPL. It is your choice, and one of the goals of the GPL too.

Thing is: there is no absolute truth. Some people think that the right way to write free software is to use permissive licenses. Some, to use copyleft. Some people think they should be free to produce proprietary software. Some people think that proprietary software is unethical and have given many solid arguments for that.
Common sense on this question is apparently non existent (yet?).

[1] https://www.logicallyfallacious.com/tools/lp/Bo/LogicalFalla...

> Tip: Comparisons of any kind almost always are flawed. Think carefully before you accept any kind of comparison as
evidence.

[2] https://en.wikipedia.org/wiki/Argumentum_ad_populum

[3] https://en.wikipedia.org/wiki/Viral_license#Criticism_of_the...