Originally, I wanted the phone to be as modifiable as possible. As part of this, I wanted to have a system where the screen could be replaced with any type whatsoever. I had set up a system where you could have two completely different types of screen, and you'd be able to swap them while maintaining 100% compatibility without needing to recompile firmware. Unfortunately, the benefits just don't justify the cost of having this system. It slows down the display by quite a bit, and it adds unnecessary complexity to the phone, which makes it harder to repair and makes repairs cost more ($30 screen replacements vs $10, things like that) so I've just decided to scrap it.
TL;DR: Old system of interfacing with screens was slow and expensive. Getting rid of it.