We tend to consider conspiracy theories as mere nonsense, like Friday the 17th.
However, conspiracy theories have the effect of diverting attention and understanding from the true reasons behind events. If I think that immigration is the result of a conspiracy by obscure Zionists for obscure reasons, I no longer understand the reasons (evident to others) why masses of people risk death in deserts and seas, and why Westerners try to push them back.
Similarly, the world behind HAMAS attributes the backwardness and poverty of their world to obscure plots by the great and small satans, and thus fails to find the path to progress, as has been successfully done in the Far East.