"guns?? why so many??? " erm, who cares? either they want to model a gun because they feel like it and they want to, or they need to for a job or because they want to see if they can do as good or better job than the gun they just saw on some site. either way, any model you create is good experience.

"guns?? why so many???", thats like saying why do artists draw so many flowers.

anyway, maybe theres so many guns cos they are all crazy trigger happy loons! :p