The openness of maemo has more to do that it is a standard linux distro and not some sandbox environment like the others. And also by the fact that Nokia puts no restrictions on what you want to install, ever.
You don't have to go to some shady website and do voodoo magic to get root.
If it saves Nokia some headache by doing it as a third party package, legal or financial... I have no problem as long as they still allow me to do what ever I want with the phone on my responsibility.