I would agree with much of what you're saying.
Managing named caches is a real pain especially considering the elevated roles required to set up caches. (Sybase roles don't really work well in our company where DBAs are a separate off-shored team).
So we fix that by binding certain databases to certain caches as we know some databases have the "main" data so we don't want that flushed out.
Its just an attempt to give better performance as we know that 25% of the main databases are in caches and 10% of the other databases are in cache.
No idea how effective it is though but it seems ok
