It's not up to KDE to decide "what packages do we want distros to ship". 
That's up to the distro. Packagers are perfectly capable of creating packages 
with whatever level of granularity they want. They're the ones who will 
decide how to split stuff up, what features to backport from trunk, what 
parts to leave out, what extras to include, etc. Some will want a single 
kdelibs package, while others may want to split it up into a dozen packages. 
KDE should not be trying to second guess them.

It might save one distro a lot of work, but inadvertently create a lot more 
work for others.

There is still great benefits into making things easier for distros. But that 
can be done with better docs, more build options, etc.

IMHO,

-- 
David Johnson