I'll preface this by saying my partner and I have been actively living fitness/bodybuilding-oriented lifestyles for quite a while, so we understand the motivations behind why people use these sorts of tools.
While some people are into Fitocracy simply because of what it is now, I think many are spending time on the site for the promise of what's to come. We're still very early stage and we have a lot more planned beyond simple points and badges. Many features on our roadmap are being designed precisely to help users push themselves and keep consistently progressing in their fitness.