This is like saying that people who lost everything in trading go into crime...I doubt this is the case.
Gambling owners can make the gambling environment decent and crime free if they want to. Some are probably encouraging that kind of environment to attract more gamblers.
Crime can be a side effect of gambling habits and can be done outside the gambling environment. Even though casino owners can make a decent and crime-free gambling environment, it's only a view from one angle. Because bad gamblers can commit crimes in other environments and bring the money into the casino.