In this case, the relationship of "master" and "slave" is intrinsically linked. No one is telling you to stop using "master" in other contexts. It is the master-slave relationship here that is the issue. You are beating down a strawman that wants to remove the term master in all contexts.
In the context of this thread it might be a strawman, but there clearly exists an initiative to remove usage of the word master, even when not paired with ”slave”. One such example is the use of ”master” in Git contexts.
