Those were designed to fit into places like "classy" restaurants or businesses - small, unobtrusive, "blend in to the background" Ha ha, yeah, right. But that was the thinking - back then a lot of places were still wood paneling, wood grain (even cars) and having a smaller, less flashy game was more acceptable in some venues.
I personally LOVE cabaret's - wish I still had my old ones. Best ones were from Atari - they fit a 19" monitor in theirs, but managed the smaller size in spite of that. Tron Cabaret, Centipede, Tempest - would love to have those here.