apt-get on Harmattan is not the same as apt-get on Debian; it's a patched version to suit the eccentricities of Harmattan.

For e.g. the priority of packages from Nokia Store, the dependency of all packages on the meta package etc. Unless you remove these dependencies, the removal of meta package will leave you with an empty system as all other packages are uninstalled too.

Search around and you will see the different examples.