I agree with the sentiment here. Discourse uses some terminology that makes us seem complicated and technical, out of reach for non-techical people, and the word user is one of them. We also use some common words in uncommon ways, or in ways that are particular to Discourse. For example staff and groups, and the labels we put on trust levels.
Cakeday is another, meaning “member since” - though I am told that originated on reddit. Just came up again in Usercard Redesign Experiment - #10 by tobiaseigen.
Even the use of the word software is a bit problematic. Yes discourse is open source software, but we do not need to emphasize that fact everywhere.
We wouldn’t want to rush into changing these from the defaults for the reasons outlined above, but it’s a good idea to create a list of them and start thinking about introducing new words that are more accessible to non-technical people.