Why do gamers do this?

Gamers should not be dissatisfied with a game they can willingly not buy. They didn’t have to buy the game and pay for it yet they willingly bought it and spent their money and then criticize it and complain like hell that it’s bad or not what they wanted or expected. I don’t get it. This is why i research games before i buy them or do anything
Why do gamers do this?
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