Why would anyone gamble in general?

Some people say that they do it to make money, and those people either misunderstand simple math and statistics, or choose to ignore it (much like some people mining BTC at the moment on inefficient cards and hoping to make a profit, without taking into account electricity costs and the like).

The real reason is (probably) that they're willing to pay 3% or whatever for the entertainment and exhilaration that the gambling provides them with.