At some point, aptitude changed its behaviour and didn't tell anyone.
It used to be that you would start aptitude, and you would find a list of available updates, from which you could select those which you wish to install. Easy. That was obviously too easy, as the new behaviour is to, by default, mark all available upgrades for installation, even the broken ones, then try to sort out dependancies, and mark for deletion packages which will be broken and you wouldn't need anyway, like KDE, or BASH. This is sub-optimal behaviour. Moreover, it is rude, and it took far too long to find the combination of settings which turned it off.
This means that every time I started aptitude, I would have to go through and un-select the packages I didn't want updated, ie., almost all of them. That's a lot of packages. This is long, time consuming, and prone to error. When an error occurred, there is no easy way to see which packages have been chosen to be removed because of broken dependancies (which the package manager's stupidity broke), short of the check just before committing the changes. This is often not enough. Because of the webs of dependancy, I would usually find that the packages thought to be broken, and therefore unnecessary, would include KDE and GNOME. Wheee! As it is, something has fscked up KDE's Mime recognition, which means basically that most of the functionality of the desktop has stopped working, and only guessing the right packages to reinstall has kinda fixed it. (Although it did stomp on various personalisations I had made. muttermuttergrumblefscking$*#@!.)
Long story short, aptitude has made the last two days a fair misery, as I try to restore amends, in between actually working.
I just needed to vent. And let this be a warning to you all: All software sucks, and if it doesn't now, it will in the next version.