"A well-known aphorism is that Unix’s method of
portability and backwards compatibility is source code
distribution. With well-written source code, a simple recompilation
fixes most binary-incompatible changes. With a binary driver, when
you can’t recompile against a new library, you may be unable
to upgrade other parts of your system.
"This can be a problem when you need an updated kernel to use
another feature of your system — or another driver. This can
even be hazardous, when the update involves a security fix."