All in all, the FSF is arguing for restrictions about how one class of individuals may use what they produce and for the benefit of the other class. Just like how FSF prevents other developers from using their products to lock other users out of their software, similarly, the employees are asking to prevent ICE from using their products against the questionable imprisonment of other human beings.

But I think the main difference lies in that copyleft limits itself purely to the realm of controlling how modified software is distributed. The only thing it limits is how modified software is distributed. The only thing it requires is how modified software is distributed. When a developer writes software to be used by others, it's necessary for the developer to decide how to distributed it, and copyleft provides an answer. Copyleft doesn't venture past the developer's necessary role.

On the other hand, limiting providing stuff to ICE ventures out of the developer's necessary question of how to distribute software and now starts thinking about human suffering, jails, politics, etc. You've gone past the question of how to distribute software, and are now thinking about broader topics.

Developers are allowed to create commercial or otherwise restricted software with FSF tools like gcc.