This Stallman quote (transcript from an interview) may be instructive here:

"And the issue doesn't really arise for software that goes in a watch or a microwave oven or an automobile ignition system. Because those are places where you don't download software to install. It's not a real computer, as far as the user is concerned. And so, it doesn't raise these issues enough for them to be ethically important."

Source: http://www.gnu.org/events/rms-nyu-2001-transcript.html