But if Ubuntu bundles an Nvidia graphics driver that is not open source does that disqualify it? It's normal for there to be a mix of both open and closed source code in an os.
A better example is: I install Debian and later, somehow, the Google Play Store. Maybe that’s the only way to get some driver. Who is responsible for asking my age: Debian or Google?
I think what matters is who is in control. You can always ditch the Nvidia driver and buy another card from a different company. Even if that one is not open source, you're the one in control.