Different people can interpret words differently. Replacing 'master' is a very low cost change which, IMO, can improve understanding of what is described. (Like main or root branch or vault password.)

So why cling to a word that has so much cultural baggage when it doesn't even work that well in Thunderbird?

But the word "master" means a lot in tech. This is like someone changing the word "save" to "store", after many years of use in tech, and everyone knowing the implied meaning, but some minority of users are complaining that "jesus saves, data is stored".

  > So why cling to a word that has so much cultural baggage
  > when it doesn't even work that well in Thunderbird?

What cultural baggage does the word "master" have? And before you throw around the word "slavery" my grandfather, who passed only 14 years ago, was a slave. I have no qualms with the word "master".

> ...why cling to a word that has so much cultural baggage...

Clinging? We're all just talking here and we don't have any authority over this software. Are we allowed to have differing opinions about what already took place? I think so.

Personally, my opinion is that I laugh at these people for their empty virtue signaling that really doesn't help understanding here in this case. We don't have to be clinging in order to discuss how idiotic we think things are.