[hresvelgr]

It's solving problems that are so far down on the list of priorities of a video game project that it will never evolve beyond a mere toy unless they really wise up. "My performance is bad because I didn't design this in a data-oriented way" is a different problem when 65% of your game is finished as opposed to solving it at "Hello, world." Hell, you can't even solve that problem unless you understand what your actually real game is doing at a data level in the first place.

Before software can be reusable it first has to be usable. There is a good reason why every existing popular engine was purpose built for a game in its infancy.