BTW, it's not a theory, and yes Islamics have used pot down through the centuries for various evil purposes, e.g. getting so toked up they'd kill their own mothers, maybe you, certainly your dog.
Wow, man, you study that Islamic history and they'll tell you all about what pot does to totally destroy a civilization. Sure it takes a bit of time but look at the Middle East today.
Do you want to leave that as your legacy for your grandchildren?
I believe that allegation of its word origin is open to interpretation among scholars, or so I have seen in my quick glances on the subject. Islam condemns the use of any and all intoxicants, and apparently there have been many debates over the centuries about the properties of hashish and whether it should so be classified as an intoxicant or not. Hence various Islamic cultures reverted from tolerating or condemning its use as unIslamic from time to time.