I never told anyone to do this my way... Car example is very bad. When you own a car, it is up to you how you want it to look, where to fix/do it yourself and so on. I like Leadwerks, but right now it dose not fit my needs. I have many bugs with it and i know that Josh will never fix them. They are on all levels, from Editor to Core. And i dont want to spend years by waiting Josh to fix them.
What i tried to tell, it is up to you, if you want to learn API just do it. But in my opinion you will learn much more about how everything works and how to optimize or design when you doing it by yourself. And if i want to build a RTS game, why do i need to be worried about wrong design, which doesn't fit my RTS design????? I could make this list very long, and everything have to do with Leadwerks closed sourse.