Yes, but distribution (or propagation) without permission is an infringement of copyright law.
Not with GPL. GPL is a license, not a contract.
Quite contrary, as the matter of fact - it is enforcing distribution without requiring any permissions, except providing the license
We also can not make proprietary modules. If we could, it would be a different story.
True. The GPL states that you can use the work for commercial or non-commercial purposes, that you can modify for your own use and that you may re-distribute (or propagate) that modified work.
Which exact line in the GPL license made you think that users can modify for their own use only?
So much condradiction in the way you think about this. How can anyone use the work for commercial purpose, while, at the same time, be modifying it for his own use? He is not going to sell that work to himself, is he?
the bit you're overlooking is that this re-distribution (or propagation) is still subject to the definition of propagation (which requires permission)
Again, definition of propagation we are referring to does not say anything about permission to propagate.
Let's think this way - I sell someone my module (which must be released under GPL, because OC is GPL) and I do not give them permission to sell that module, unless they provide me with some funds. Does this sound OK? From the moral point of view, it does, because why should anyone earn from hundreds of hours of work I've put into that, while I don't receive anything? But, from the legal point of view, I have to abide to GPL, which allows them to do so.
On the other side, we all end up earning from MySQL while not paying anything to SUN, so everything is back to normal
Actually, the fact that they are selling, makes them liable, and removes any liability from you.
Not the fact that
they are selling, but the GPL license itself
I really am not trying to deprecate your point of view, but you seem not willing to accept that it is how it is.
I was holding up from saying this, but a friend of mine had problem with a Drupal module he coded for one of his clients. He had taken them to court because they sold that module to the 3rd party. Long story short, he ended having to pay court taxes. GPL allowed them to do that.