I think - or, better, i know - that they were not a mainstream thing, so, AGAIN, saying that something "could be modded in" in 2001 is something very, very wrong in this thread.
Again, if you imagine a common person in 2001 (common = regular PC user, buy a game, install, double click on the icon to play) being able in 2001 to find, download, apply mods on a game, then I think that your parallel universe would have been more interesting than mine. I guess that 1 out of 1000 PC players tinkered with mods back then, and I'm probably being large with the estimate.
And I close here, because, we are horribly OT at this point and I really think that we are going nowhere with this interesting excursion in alternate 2001.