It is deemed a qualified use to limit gambling because gambling addiction hurts more than just the addict. Their family suffers, maybe society suffers because of crime. Limiting (not outlawing) allows for outreach, voluntary blacklists, escape for their family should they cross the line and other safety measures.

As for the brightline between economic decisions: yeah, the definition is not perfect. Poker isn't gambling for some definitions because it is 'a game of skill'. While buying a plot of land with oil is certainly a skill AND it is expected to generate profits. But we can't protect as m well against hopeful stupidity.

Buying an insurance policy isn't gambling as it reduces risk. ...selling one is gambling if you didn't do the math though.