"Theoretically, no one supports gambling. but practically, there are a lot of people who support it by participating in it."
*Some of them build gambling platforms, some people become gamblers, some participate in promoting the gambling platforms. Also, many other people support it although they don't join on it directly. That's the fact!
I cannot recall there is a group that supports gambling, except those who are in the gambling industry. And it only account small minority of the population.
Even many gamblers won't support gambling because it ruined their lives. Take part as a user doesn't mean he supports the activity because of the addiction forces him to gamble. The situation is similar with cigarette industry where only those who work in the industry support it.
Anyway, context is important