However, people still gamble for various reasons.
We can assume that the people who still gamble are not from the religion that prohibits it or if they are they are not very religious. In reality too, almost every religion is averse to gambling, Islam is the only one I know that expressly prohibits any form of riba which will include gambling and also investing in Bitcoin, but Christianity is not welcoming of gambling either or any other religion for that matter.
I do not expect anyone to openly here discuss how they participate in something that is expressly prohibited by their religion.
I believe that there are still people who play gambling even if their religion restricts it. It is the same as to those who still do a crime and other illegalities even if they knew that it was wrong.
Yes, a very religious person is too kind and won't do things that they think are not generally accepted by the public including gambling even though their bible didn't say anything to it, or didn't say that it was not allowed. Really, Islam restricts BTC investing too? Damn, I think that's crazy but how is it possible when BTC have only existed in 2009/2010? I think what can mostly restrict BTC is the law or the government but they also can have it anyway.