Well, I'm still working on the 2009 catalog, the first snail mail catalog in over a decade and I'm remembering very quickly the reasons why I was so very glad to give up issuing catalogs in the first place.
Picking a theme and the books to go into the catalog is not a problem. The problems are with the actual formatting of the catalog. Decisions like whether the catalog will be full page or booklet size, items separated into sections and what those sections should be, what items are to be illustrated and whether the illustrations will be with the listing or in an insert. These are the decisions that just drive me crazy (crazier anyway).
I also think that when you make a living selling the bound and printed word, there is an extra pressure to not produce a crappy looking catalog. So it is always a balancing act between time and cost involved in producing and proofing a catalog and the need to get the blasted thing finished and mailed so it can pay for itself and move QUICKLY from an expense and into profit.