Comment 6 for bug 119467

If peaple deinstall a default application they choose not to use the kubuntu-desktop default package selection so kubuntu-desktop is removed.

If new packages are added in a new release they will not get them by default because they choose not to use the default package selection. They can however install them manually, so where is the problem?

You have to decide between default package selection and customized package selection you can't have both.

aptitude installs recommended packages by default apt doesn't.