An analogy I once heard at a discussion involving evoloserism which struck pretty much everybody as unusually funny:
Picture it being about 1965 or thereabouts at the absolute height of the popularity of the little VW beetle-bug, and the evil Dr. Fu Manchu devises a way to get rich in the grand-theft auto business by creating a machine to steal large numbers of the beetle-bugs; he takes a plastic mold of a beetle-bug with its doors closed and windows up and shortly has fleets of large trucks going down the streets at night with huge vacuum devices ending in hard rubber attachments which fit straight over a beetle bug, attach to it via suction, lift it up, and put it in the truck.
Shortly all VW owners are living in mortal dread, and are chaining their beetle-bugs to large trees at night.
All except Suzie Johnson that is. Suzie crashed her VW into a tree at about 12 mph; bent up the hood, the right front fender and the passenger door rather badly but, other than that, it still runs decently enough. The frame wasn't damaged and the engine and drive train were in the rear. And, naturally enough, the damage would prevent Fu Manchu's device from fitting her VW or stealing it.
The 64,000 question is, would anybody refer to the crash damage as a "beneficial mutation"??
That is, more or less, how all "beneficial mutations" for bacteria operate, that is, the mutations which allow them to survive specific antibiotics, and that's basically all that anybody has ever proposed as examples of the "beneficial mutations(TM)" which are supposed to drive evolution; the microbe loses whatever it was that allowed the antibiotic to attach and attack it.
That or sickle-cell anemia, which is supposed to be "beneficial" by preventing malaria. I could however "save" somebody from ever catching malaria by shooting them through the head with a 44, and I don't really picture anybody calling that "beneficial"...
In real life, mutations have names:
and the normal English language term for mutation is "birth defect"