To answer Dizzy's question:
Because it's there and it can be done. Why paint a picture if you can make one that looks better using your digital camera?
heck, an 68040 should be powerful enough for that particular game
I highly doubt that. It might be powerful enough to run the game, but not to play it at any acceptable speed. The only 3d game that ever ran well on my 040 was Frontier, and that didn't have textures. Duke3d is a lot more cpu intesive than Doom was.