Speaking as a UX designer, probably because some "product manager" decided it was too expensive to override the auto- sort that was applied before the designer was brought in to "pretty things up."
There is no tone of bitterness in my comment, honestly there isn't.
Yeah, I was going to say they just left a default alphabetical sort to their global droplist component and called it a day. Probably works fine in most contexts, but this one - not so much.