It's all a secret plot by Muse, they're gonna reel us in with small items like badges which we progressively unlock up to the point that we obsess over collecting 'em all. Then they'll convert GoIO into 'Badge Simulator' to rival TF2's 'Hat Simulator' and make millions.
But seriously, some people don't care about this stuff and some do. It's always nice to have something to work towards even if it seems pointless to have it in the game. Someone mentioned 'why have achievements', but some people just like having little things to work towards and its always nice to have bragging rights even if you can't brag to anyone about it