> A human being doesn't violate copyright in learning from a copyrighted work, including when that human being is later more able to produce other works based on that learning

You have to be very careful with this line of thinking. I remember SCO versus RedHat began on much smaller premises. I also remember it took years for ReactOS to audit their code after mere suspicions arose about code that seemed to be inspired by something like asm to C translation.

The GPL is clear: derived works must be under the GPL too. The license must be respected, it doesn't matter if it was copied "from inspiration because it was learned" by an algorithm or a person.