Right to be offended

The problem is, you can find people that react emotionally to everything. Literally everything. Attempts to accommodate them all often lead to ridiculous results.

On the other hand, if a sizable minority tells you that they don't like the term - it's probably a good idea to stop using it. And it's the first time I've seen people being offended by "master/slave" terminology.

Also you should keep in mind that "master/slave" names migrated into technical jargon in several other languages as loanwords (I can vouch for Russian, Ukrainian and Czech). They are completely neutral and many technical professionals don't even connect them with the original "master/slave" meaning. So for better or worse, this horse is out of the barn.