Many of the humor in Fallout 2 was because they were running out of time and had a lot of areas that were very empty. They had to come up with things in short notice.
Remember that Interplay wanted a game twice as big as Fallout 1 but that felt less empty. All of this in a very short amount of time to finish and release the game (around 9 months IIRC).
The graphic and model teams couldn't even finish all the things Black Isle wanted to include in the game, so many things that were actually well planned got cut out.
Then they had to come up with quick content to place in the game using the resources they already had... Humoristic pop-culture references are the easy way out when you have to fill a wasteland and some settlements with forced content and are running out of time.
I found a nice interview that illustrates the problem:
Feargus Urquhart said:
We'd started working on Fallout 2 before we'd even shipped Fallout 1. That was in the middle of 1997. By the beginning of 1998, when Interplay was having some financial difficulties, they decided they wanted to make Fallout 2 and make it in the same amount of time as the original, and as far as they were concerned, we'd already been developing it for half a year already. So that gave us basically nine months to make the whole game.
Eric DeMilt said:
Fallout 1 was amazing, it really knocked it out the park. But Interplay launched it right before launching Baldur's Gate, and in terms of revenue, Baldur's Gate absolutely smoked Fallout - Fallout initially sold something like 200,000 units while Baldur's Gate sold like a million. And it was a much bigger game. So when we kicked off Fallout 2, there was the ambition to make it as big as Baldur's Gate, and that's where a lot of the pressure came from.
As well as a hectic development schedule, that extra pressure led to Black Isle creating and calcifying what would become some of the Fallout series' most-famous trademarks. In the case of dynamic, fleshed-out characters, this was on purpose. In the case of bizarre and often hilarious glitches, it was by accident.
To meet their tight production schedule, designers would often have to draft huge game areas and then move quickly onto the next, leaving vast portions of Fallout 2 sparse or underpopulated, right up until its release date. It was a harried way of working, but it actually helped to cultivate Fallout's absurdist visual style; with swathes of the map still requiring characters, missions, and other playable material right down to the last minute, Fallout 2's artists and programmers were creatively set loose, and developed appropriately strange ideas.
Dan Spitzley said:
I basically sat down and thought up everything and anything I could to fill these spaces. That's where a lot of the crazier stuff, like the treasure-hunting dwarf or the Radscorpion that played chess, ended up coming from.
Eric DeMilt said:
Back then there was collaboration. Our team was pretty small and there were no strict guidelines for how things got done. It was a like a Wild West development style. If you had an idea and could get it into Fallout, then we'd say 'yep, do it’.
