As for why they would be so short, my theory has always been that the ratio between width and length from back in the day sort of stayed with us until today.
Basically, 31" used to be a normal length for street decks. If they were wider decks, they would also make them longer, as these were mostly used by transition dudes or whatever.
As skaters started using progressively wider boards, manufacturer's would produce them using the already established ratio for wider decks. As time went on, people just got used to decks being longer.
So when people talk about decks getting wider, they actually just got bigger all around. It's really only recently that we see more variety in shapes and dimensions.
I wasn't around in '94, but I have been observing this since the early 2000s, as I've always preferred a shorter board, regardless of width. Back when I used to skate 7.6", the length was usually hovering around 31", but as the standard width started creeping above 8", finding decks under 32" in length started to become a challenge. I actually skated Girl and Chocolate decks exclusively for a few years from about 2007, as I could always find an 8"-8.1" deck with a <31.5" length. Then they changed, and I was on Death skateboards and Dan Drehobl's Krooked decks for a while. Now I finally feel like there's more variety, so I try everything now.