copyleft really doesn't restrict, copyright does. copyleft only delimits the permissions so that everyone can do whatever they wish with the software (freedom), but without granting them power to deny that freedom of others (power). without that grant, they can't abuse others because copyright won't allow them: that power remains reserved to authors, as even democratic societies adopted.

now, "use" is a loaded term. a lot of laypeople people misunderstand that as running, but under copyright law, it means adapting, modifying, using parts or the whole of the work to make others. enjoying the work (reading, listening, watching, running) are not reserved. this means copyright law does NOT empower author-itarians to dictate terms of use (execution), only terms of use (adapt, modify). that's why those who wish to dictate such terms resort to contracts (AKA licensing agreements) that, along with permissions to do activities that copyright law reserves exclusively to authors, establish obligations that are alien to copyrights, and require explicit assent, such as click on "I agree", breaking a seal or such.

now, not taking their patches, or not even looking at them, may be foolish. they may have valuable contributions to make, even if operating under oppressive regimes, or even while holding repproachable ideas in their minds. someone once said something about hating the sin, not the sinner; someone more laic said something about not imposing collective punishments. human rights that people often forget when they're driven by (under influence of) propaganda and moral panics