Longevity with fair to bad reputations. What a gambler should look for in a casino is reputation. What people should be expecting from the casino now is accounts restricted from withdrawing. It is possible that the casino misappropriated their customers money and not having enough money as before.
The thing is that many gamblers just invest in random sites without checking their reputation in advance thanks to getting tempted by their promotions, high value odds etc and end up regretting later on.
Greed is the problem here. Smart gamblers do their research properly before choosing a casino to invest in as you mentioned yourself.