And then you end up with explanations like "Gravity is like a deformation of a rubber sheet". Completely misleading. In a similar case (not physics), I literally wasted years on trying to understand something correctly because I wriggled from analogy to analogy instead of putting effort into learning it correctly.

> I would use analogies with things they already understand, such as the hydraulic control lines of steam-powered machinery

How many people from the 18th century knew how those worked? You would be talking to an elite engineer. And even then you would first have to explain to them how you can represent numbers and numerical operations with those valves. I am pretty sure that if you take a today's elite engineer and take the time to explain him the basics correctly, he would be able to understand theoretical physics. That's what's happening in universities every day.

> If you argue this point, first explain to me why physics is done with Greek letters.

There are probably some historical reasons for that, but today it's just because you are quickly running out of latin letters in complex equations, at least that's my opinion :)