HA!
So I am not the only freak around here
I thought of another reason why the publishing date might be of interest: Authors sometimes re-publish their books to make them more contemporary, remove references to "dead" technologies (such as car phones or LPs) etc.
But using the "Series" field (which is awesome, by the way, but strange since most programs/databases/etc. do not give this info) is a plausible "plan B" for my needs.