I consider making for a living is where you can always make money in long term, gambling can make money but it's just only for few times and it's impossible if you're only depends on gambling as your main source. Gambling isn't a long term money making because luck isn't always in your side and there's a chance you will get scammed from fraudulent casino. Not to mention your account might get frozen, restricted or betting limit.
In probability, there are some guys who gambling every day, and they can make a living from gambling, although they might not win every day but they win every week, and there are some times the ones they win once can cover the expenses of the week, and if probably he wins twice a week then he has nothing to worry about. And in a real sense, it will be very hard for someone to make living from gambling. As you said, account suspension and other things are always involved in gambling platforms.
Those who win that way can also lose everything they have in a single week if they can't manage the risks especially if they are compulsive gamblers. Yes, anyone can make money from gambling but we can't rely on our daily living on it. In terms of stability, gambling can't be a reliable source of income. If we will rely on our luck to survive our daily or weekly expenses, we might only end up losing everything we have because of chasing our losses because of too much hope to make money. Those who win consecutively are also those who are risking a huge capital in gambling. We should not disregard that gambling is risky and not everyone can be lucky with it.