It frightens me that the word Taken is so often used in place of “In a relationship” or any other phrase used to express that you are not single. It just sounds so strange, scary even. Taken. I don’t know. Maybe it’s just me.
It isn’t just you. But do consider the symbolic nature of their word choice: Those that are using the word “taken” in lieu of “in a relationship” could be viewing relationships as situations in which they own the other person and the other person owns them.