Actually, yes they do according to you. You're the one with the "just scale it up" attitude, not me. If your theory holds any water (which it doens't) then it wouldn't matter what you're talking about at all.
You've already stated "just scale up a rocket". That means the rocket, engines, fuel load, all of it. If you're going to suggest that, then it would hold the same for anything at all, including the internal combustion engine.
If either one doesn't hold water, then your entire premise doesn't hold water.