Yes, "copyleft licenses force or encourage devs to contribute back to the community" is a ridiculous cliche (or misguided, or misleading, to be more charitable)

Yes, "copyleft licenses force or encourage devs to contribute back to the community" is a ridiculous cliche (or misguided, or misleading, to be more charitable), but for different reasons than you talk about. The point of Copyleft (and the Free software movement in general) is to ensure that the user of a computer (and the software in it), a human being, is free -- meaning she can do with it what she pleases. Use if for whatever, study what it does, change it, share the original or modified version -- those are the four freedoms https://www.gnu.org/philosophy/free-sw.en.html https://www.gnu.org/philosophy/free-sw.en.html . Humans can't be free, if they're not in control of the computers/software that they use. The Free software community considers it unethical, if a cellphone owner or an automobile owner can't do with her device (including the software it runs) what she wants, even though she bought it with her hard earned money.