I believe everyone should be able to audit & change the software they run, or hire someone else to do so.
That does not mean I don't believe in paying devs (paywalls, especially softpaywalls, seems like the best way).
And it does not mean I believe all software must be public for all to use, feel free to keep code for internal use or share your code only with your customers.
You only need to agree to the GPL to redistribute your possibly modified copies. Because as per normal copyright law you wouldn't be permitted to unless you had a document like the GPL stating that you that you can! In other words if you didn't agree to the GPL & redistributed those copies you have no right to do so.
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