Right. And the fact that you don't find those terms offensive is part of your privilege. You're being invited to step outside of yourself and consider that for some people, it's not as clear-cut / apolitical as it is for you.
My argument goes more along the lines that changing something like this can cause more harm than good in some cases, given that we have years of established documents using these definitions.
As an example from science, the reason that the direction of conventional current goes opposite to the flow of electrons is because we found out new information, but decided it was too costly to change.
If we remove the Master/Slave terminology from everything new effective today, then in 20 years, will a new developer know that 'Main/Secondary' in their 2021 datasheet is referring to the same thing as 'Master/Slave' from their 1991 datasheet?
Possibly, but also maybe not. A smart person could infer this and another could search it, but there is still potential for confusion.
So, say we start using main and secondary. Someone smart enough to be reading a datasheet will probably figure this out. Right? I work in several different programming languages in any given week (SQL, C#, JavaScript, various data formats, and so on). I don't get confused when the name of a data type is a little different between these.
I am not trying to be rude or mean, I am just saying we can change terms. I mean, my god, we changed from Imperial to Metric while I was in elementary school. We changed an entire system of weights and measures for an entire country (Canada). That was a big deal.
Going from master/slave to main/secondary (or whatever) is not a big deal.
It's like "rule of thumb". I no longer use this phrase. Most people have no idea that this is based on how a stick a man may beat his wife with must be no thicker than the size of his thumb. But some people do. I do. And, yeah, I am sure this will be a "turns out" where a cabal of feminists spread this rumour to make white men feel bad, but I don't care. I don't say it any more. I figured out a new way to talk about a general guideline that is widely applicable and simple.
It's not a big deal.