This seem to be something that's impossible to argue against. Billions of people use cars without knowing anything about combustion physics. How many people who travel by planes know anything about aerodynamics? How many people could explain how electricity works? How many people who use computers and smartphones every day know how to code? And even from those who know how to code, how many know assembly languages and machine code?
People don't need to know how a technology works to effectively use a technology and enjoy its benefits. Successful bitcoin adoption shouldn't require everyone who wants to use bitcoin to become a computer expert.
It is impossible to argue, but I will try. You want bitcoin people to be passengers on a plane, people who don't know aerodynamics. The only person who probably should know that is a pilot. In such system, the pilot is a single point of failure(suppose system itself has no bugs), because if he fails, no one can fly the plane. Bitcoin is a plane with many pilots. The more pilots on a plane the less likely the plane will crash. How many pilots do we need to successfully aviate? It depends on how hard you want to survive the flight, I would prefer the situation where everybody is a pilot, the system is 100% safe in this case.