I personally benefit:
I've updated DDX only on many occasions so far. Usually that works just fine and I've been able to easily get important bugfixes and performance improvements this way. There are PPAs just for driver updates on Ubuntu, so I'm sure many users benefit from modularized drivers exactly like me. For example, for Intel users it should be a no-brainer to install the updated 2.12 DDX, as it offers really great performance improvements and a few bugfixes.
They sometimes like to stick to a certain driver version or offer updated drivers.
While a non-modularized model might make the life of developers a bit easier (but I'm not even sure about that regarding hardware drivers), it makes the life of users and distributors harder - a full update of X can break all kinds of stuff, and history has shown that's not only a theory.
Also, API/ABI stability might be handled more sloppy than today eventually, which is a bad thing especially for blobs.
This de modularization is a very stupid idea.
Somebody should really persuade Keith to nt do this kind of stuff.
Making life easier for developers? Is he kidding.
e.g. A random graphic driver developer: "Every time I want to compile the driver I'm working on. I'll have to compile the whole x server. This costs me a lot of time."
easier? Not exactly
All drivers should be de modularized. Everything that's not a driver can go de modularized with the x server for my part. But really for the drivers, come on, what is he thinking