It really doesn't matter if there are some of the fake bad reviews by the frustrated gamblers or sometimes deliberately forced negative reviews by other competitive casinos. In both cases, they can be easily overlooked if the casino itself is good and the genuine players are happy there as they will oppose those reviews, or there would be many better statements from them about the casinos.
But having some bad reviews on a gambling casino still damages its image. It makes new users to be skeptic to try that gambling website. Genuine users will oppose but as a new user you will definitely have doubts if you read some negative reviews.
That is why users need to search for more news about the casino and compare between the news. That will make them know the real situation on the casino and they can decide it later after they consider it.
If the reviews are telling about the bad of the casino, but the casino still trying to resolve the problem while they don't have much bad things before, new users can considering to choose that casino. But that will depend on how much info they know about the casino.
As a wise user, we need to research and check all things before deciding. That is a prevention that we can do from the scam casinos. We need to responsible what we do so we do not regret it later.