@grimmware i think strong copyleft is imperfect, and not necessary/desirable in all cases, but it's a bit like herd immunity: enough of it in the ecosystem is a bulwark against total enclosure by the megacorps.
my thesis is that if this weren't the case, the megacorps wouldn't be investing so much energy in killing copyleft (partly by way of convincing everyone that it's uncool and its proponents are just dogmatic idealists).