90% if not more of web startups from the last 10 years would not exist without free software. Is it entitlement that Facebook has closed-source software? Dropbox? GitHub?
Canonical's primary product is Ubuntu, which is, to first order, a repackaging of Debian. Facebook and Dropbox just use free software. GitHub is sort of in between; certainly they have invested a lot into the stuff besides raw git hosting, which is why they have such a dominant position, but certainly git itself is a core part of their product.
Canonical has put a lot of energy into open source for a decade - contributing code and putting free software into the hands of millions around the world. It should be entitled (your word, different usage) to write proprietary code if it thinks that's the right approach.
If you constantly burn the companies and people who actually work on open source for not meeting the purity standard then you make it a hard environment. Honestly, there are way more fully proprietary software companies out there, or companies using but not contributing anything to open source to have a go at.
