Sometimes people just sit down to do it for fun, or to relax. I have a 40 gb hard drive full of maya scenes, most of witch I have never posted here. Most of that stuff people won't see, but I didn't nessisarly make it to show anybody, just stuff I made because i wanted to take a break from everything else, or from the "real world". I don't know, I just don't think everything has to be made to "show off'', or to get a job, some people like to read a book or do other things to realax, I on the other hand, make something in 3d
my 2 cents.