Scamming is really normal in a big business, at first they will catch you attention and they will really do their best just to trust them and if they already know that there are already a lot of people that is trusting them and they already have the money that was invested for them then that would be the time for them to scam people, do not fall for it always do some research to avoid getting scam.
and they will even spend big amount of money just to get our trust , sometimes they will build the name for long time and then will break it just for short chances.
And also these happens upon desperation , when the gambling site is experiencing lowering income and they starts to feel the pressure of the business? then they will act inappropriately so they will still make money even if they lose their credibility .
I agree to this.
Most likely this will happen when a gambling site doesn't have any license, they could do anything illegal since for sure, the people they have used on their team are not even legit, so they have the guts to runaway whenever they feel to do so, like what you have said, when they are not earning good anymore.
But if a certain gambling site do have a licence and SEC registered, I guess their only option is just to shutdown their business if they are not making any good bankroll.