Check reputation board or go through the Ann threads of casinos here and come back if you’ll still have this idea of gamblers not having interest in fairness of games or not.

As long as they are depositing money and losing it to the casino they are definitely going to question if the casino is really playing fair or if they are being cheated - take for example you spin 200 times and don’t win a single one, you’d definitely be curious and start checking them (for those who are provably fair) to see if any of them were rigged.