I also find it confusing to have two fields with the same name.
It appears that Album Artist (and the related "auto" field) have several uses depending on what a user is trying to accomplish. For instance, I'm trying to catalog a huge library of all kinds of music and recordings, including lots of non-album tracks.
To do this I long ago adopted the suggestion in this forum to use Album Artist for the last, first name to get proper sorting, and also to clean up the multiple artists problem. So, for any recording where the artist is one or more people (not a group/band), my Album Artist field is like this: "Lennon, John", while the Artist field is "John Lennon". Then I sort/group by Album Artist (auto).
Perhaps the most versatile solution would be to retain the old field names, for consistency and clarity, but allow editing of the displayed field/column/tag name.