Aptitude no longer removes unused dependencies.

[David Coldrick]

Hmm, I never knew it did that: I'd like that as a feature too (only in
synaptic).

It's also a problem totally removing an app (including config): if
that app has other apps depending on it, by default they get removed,
but not totally. And there's no way for you - in synaptic - to change
their removal parameters, without removing them first, then the app
youu originally wanted to remove, etc. Back in rpm'ish land, having to
track the dependencies yourself.

Regards,
David