That opinion may have a point. Because if we do things to make ourselves busy, it can be ascertained that diverting our minds from alah an addiction such as drugs and gambling. But the transfer that thought also has a time limit, and if we can not divert the mind, it is certain we will do it (drugs and gambling). So if we want to get out of gambling, Put away thoughts of gambling and avoid things that concerned about gambling.
I actually agree with you. People who are addicted to gambling must indeed have a distraction. Because without distraction they not stop gambling.
People need to find a sport or a hobby they love to do.