Bitcoin is a currency not a gambling, maybe the gambling they are talking about are the things we do to earn bitcoin. Like on some campaigns where we risk our time and efforts even if we don't even know if it is going to be successful. That is what I called a gambling. And I believe the real world has this kind of gambling, where we risk on things that we don't even know what will happened. So everything is a gambling I guess, all things we do are all gambling's if it has a risk of being a looser at some point. So bitcoin is not a gambling, it is what we do to be a gambler!