Taking gambling as source of income depends on individual and if you don't see it as a major source of income, so I can tell you that I have many friends that depends on gambling to make a living. It all depends on the place you come from if they don't take gambling as serious as you think. So many friends do not have a job of there own so they see gambling as a big survival slot for them to make a living and pat bills and is working for them.
We want to believe that by now we shouldn't be having a mockery of any of the gamblers around us found with this kind of situations because some don't really expect to be in such but according to have live deals on them renders them with no choice than to gamble for a living, but we also have some particular set of gamblers whom have chosen this out of their laziness to work under someone or discover their potentials and explore it for creating something to sustain them in form of a business idea.