It might sound like semantics, but too many people mistake gambling for investing and end up losing their shirts.
I was reading lots of perma-bear/libertarian bloggers, the type who predict impending financial apocalypse. I still think they have a case, which is why I still sock away some of my monthly savings in gold/btc. But I also now realise that you can't bet your entire future on one possible outcome, hence the bulk of my money going into the index fund. If I save up enough that it becomes worthwhile I might look into the Buffet strategy of individual stock picking (he says with a small amount to invest you can make superb returns in well chosen small-caps).
Bitcoin is a pretty great investment asset actually, since there is a finite, limited supply, and any sum can be transferred nearly instantaneously.
It's the same as seed stage startup "investing," which is likewise really gambling, and you either have to diversify heavily, get very lucky, or have the ability to influence the outcome yourself to win in the long run.
Buying bitcoin as an investment is more like forex trading (in fact, that's almost literally what it is), which is zero-sum.