"If we compare proprietary software to slavery, D/s is more like choosing not
to assert control over a libre program than choosing to use a proprietary
program. "
Well, according to your statement about D/s
" It's just someone choosing to submit to someone else and taking on the
title "slave". Because it's not actual slavery, you can back out and
otherwise assert your right to freedom."
proprietary software fits perfectly to this description.
You _can_ back out of the "slavery" of a proprietary program anytime, without
being whipped.
Once I install microsoft office on my computer, that doesn't mean I will
get punished if I decide to get rid of it - I can just delete it.