Because we always want something new, new design, new games, new features As it seems to us.... And we can not immediately know that this is a second-rate site, even if we heard somewhere that the site has a bad reputation anyway we are relying on their experience goes to check it 
You are right about this, and also playing in small bookies or small casinos is not a bad thing even though it can make our money there disappear because they turn out to be scam sites but it's not always like that, and the emergence of new gambling sites is good for competition because there will be no monopoly in this business because with monopoly will make the big one always be the most right party. Also, all of these big gambling sites started small instead of coming up straight away with their current state.