As an asset it's worthless and it's more like gambling, it's like buying a car that might be worth more than you bought it for or it might be worth less. Obviously cars depreciate but then you get a car to drive, with bitcoin you have nothing but a number on a screen.
The only thing keeping Bitcoin going is the fact that its propped against currency which allows people to buy it easily and people are only doing so because of the hype. If those same people couldn't buy it and had to mine it instead then it would be very different and I doubt we'd even be talking about it.
It's definitely worth a punt just like betting on the horses is but it's far too risky to for example put your life savings into it. It's funny that the people making the loudest noises about it are the ones who likely hold quite a lot of bitcoin.