You're right on one point, most people content themselves with a "running computer".
But we're in the hardcore fringe of community. It's by pushing the things to their limit that we make progress. Emergence of new designs, or refinement of others, are the result. Think car racing, it serves no purpose really (entertainment set aside) but the fallout from racing is more refined engineering techniques, better engines for everyone, etc... Maybe the comparison is a bit stretched by you see my point, or i hope so.
(edit) oh snap, someone made a better answer than me here:
http://forums.procooling.com/vbb/sho...970#post154970