Bitcoin is a good investment because
1. Price is looking strong
2. Bitcoin have recovered quite nicely from that big dump happened few months back
3. After the price touched 1100$ it came back to 700$ but the price became stable now at 900$+
All the facts show that bitcoin will always remain a safe place to invest into.
As long as people interested with bitcoin, it's price will always go up because the limitation of the amount will make the demand easily increase. Bitcoin good investment because that reason.
Indeed, Bitcoin really is a very scarce currency, more than some people think. Therefore, it is natural that there is a considerable upward trend in the long run. But this is not the main reason that makes Bitcoin a good investment. What makes this is a good investment, in my opinion, is the fact that the way money is issued and the functioning of the network occur in a decentralized way. And currently, there is no other system with the same level of decentralization, efficiency and stability. That's why so many people rely on it to store value.