For the same reason you mentioned...

In Nokias mind this is *NOT* a flagaship device. No matter how much we kick and scream.

It is indeed a useful tool and I would like it on my N900 but I bought it knowing that I would be making some compromise in some areas (didnt know what).

I think it is wiser from Nokia not to expose itself in a bad light by promoting N900, when it does not have voice navigation, as a navigation device "complete with dock". If they do this the harm might be worse than what actually is.