Theoretically, this is the reason we're here. In truth, the real reason is because there was nothing good on TV.
The definition of 'fun' can be slippery, and the way to distinguish between 'things that are fun' and 'things that are not fun' depends on your tolerance for blood loss.1) A better question might be 'whose fun are we talking about?' The Watcher thinks that watching contestants poke and prod each other with chainsaws and pointy metal sticks is 'fun' - but then, she rides around the Island on a large pleasure yacht, watching things from afar.2) Contestants can be forgiven for not sharing her enthusiasm about their various demises.
Now get off your butt, get back in the game, and go looking for some 'fun.' Remember, the Watcher is watching you.3)