Personally, simply because I actually really like the concept of having a decentralized and pseudo-anonymous currency. Sure, bitcoin has been gaining so much gains since years ago, but the main reason I'm actually investing my time and resources in bitcoin is because of bitcoin's objective and goals.
Why chose bitcoin? Why not invest in shares/ stocks? Other investments?
Because Bitcoin could appreciate times more than any stocks, it can get you x10 if the market is right.
Sure it can. But take note that it can also get you x10 losses