Really I'm not the best person to judge though. I'm happy to be guided by people who experience racism and groups tackling the legacy of slavery. Because those things seem important whereas my terminology preferences for asymmetric nodes in a distributed system, when there are plenty of sensible alternatives, seem less so.
Slavery was really bad, and for that reason shouln't be used as a description.
There are always alternatives, like "leader and follower"
We also kill child processes. No-one's had a problem with that till now. Sometimes a metaphor is just a metaphor.
Which is a worse analogy, because "following" is a choice and doesn't have to be strict, unlike slave (execute commands or get killed).
On my computer I can open a folder twice without closing it. I can't open a physical folder twice without closing.
With a race condition, no one cares if both processes started at the same time. That's not an important part of the analogy.
Even your point about killing doesn't really fit with the metaphor. Historically, whipping would be the most common punishment.
I do agree with your idea that the metaphor has to be clear. Modbus replace master/slave with client/server, which tends to confuse people used to the old analogy. It's not ideal, but neither is referring back to that time we could trade people.
Can you clarify this? If one machine/repo/system acts only on the orders of another, wouldn't "master" and "slave" be clear, descriptive choices of words?