[rbarrois]

I'd say that the deal is:

- With Dynamic Linking, it's the job of the system admin (typically a distribution maintainer) to ensure that the system-provided library and application are compatible — and add patches if needed;

- With Static Linking, the package developer takes control of the whole experience; they deem more important to deliver a working application to the end user than to ensure compatibility with an OS.

This makes sense for isolated applications, e.g. video games. For a system's core stack (coretools, X11, etc.), the end user expects to receive security fixes in a timely manner. From the distribution's point of view, it seems simpler to have a single library to patch, recompile and push, than to have the maintainer of each package statically linked against said library release an updated version...