“Copyleft” subverts copyright law.
Its dopey idea of imposing its constraints on all derived works should not hold up in courts, but I don’t think it’s ever really been tested.
People - including judges - know that the elites want copyleft and “free software” as it cuts the legs out from under the software entrepreneur.
Copyleft stands on copyright. It can demand royalties of standing on your head and whistling Dixie.