While I appreciate the criticism, I wonder why Bitcoin detractors' main argument is always "it will never go mainstream", while by their definition of "mainstre

While I appreciate the criticism, I wonder why Bitcoin detractors' main argument is always "it will never go mainstream", while by their definition of "mainstream" (ie. "the average person"), gold isn't mainstream either, and yet it's such a great store of value that even central banks use it.