I could not agree more with you mate. Gambling can just be one of the many places we can spend some of our money to be entertain and have fun and not necessarily make gambling as our main source of income.
Only a very few people are gambling just to be entertained and have some fun with their money. When you say that it is not necessary to make gambling as major source of income, you have to think about it again. There are so many gamblers struggling with this argument, they are supporting themselves for being a full time gambler because it is their own source of income as they are earning good with it.