Now, before I go into this, let me make a statement here: I love Ubuntu. I really do. I'm heavily invested in it both personally and professionally and, when I write Linux software, it's primarily targeted at Ubuntu. I want to see it to succeed and I want it to succeed in a big way. That said, I think part of helping the system succeed is keeping the people leading the project in check. Sometimes, when you care as passionately about something as Shuttleworth does, it becomes very easy to see everything else in a skewed 'us against them' way.
Mark seems to believe that those who criticize Ubuntu or his company are doing so because they have some personal ax to grind or that they are criticizing their code. He even likens those who oppose them as 'the open source tea party', referring to a fringe of the American right widely thought to be obstructionist. Nothing could be further from the truth. Everyone supports Canonicals right to write code and, for the most part, almost everyone agrees that the company produces really good code. The issue most people have with Ubuntu is the same issue people have with Android: fragmentation.
With each release of Ubuntu, the project seems to be moving in its own direction, further and further from mainstream Linux. The Mir display server, the Upstart initialization system, the Unity desktop, are all great examples of this. Over and over, we see Canonical rejecting widely adopted technologies in favor of designing something completely new. I'm not saying new is bad, mind you. But I think Canonical's time would be better spent improving the widely accepted technology instead of falling trap to their own version of 'not invented here syndrome'. Imagine the strides the GNOME project could make if Canonical were actively contributing to the desktops development? Or systemd. Or X Window. Instead, Canonical chose to cut its own path and start from scratch.
That attitude might work in a 'let's get grandma on Ubuntu' mindset but it certainly falls down in a 'let's get grandma on Linux' one. There seems to be coming a time, and it may be soon, where there will be 'The Ubuntu Way' and 'The Linux Way' and those two might be widely divergent. And, yes, I know all of the technologies are open source and anyone could use them. But the fact that almost nobody but Ubuntu has chosen to shows that the industry has spoken and congregated around other technologies for whatever reason. Perhaps Canonical should look around their growing island and see that it's largely populated by themselves and almost nobody else. Perhaps that should tell them something.
In the end, it's not just about code. It's about the unity of the open source world. In the face of intense competition from well funded and profitable companies like Microsoft and Apple, the last thing the community needs is fragmentation. We should be making it as easy as possible for new developers to write applications that work just about any Linux platform, not just the most popular one.
So, Mark, write code! Write good code! Nobody is going to try to take that right away from you. We're just all a little concerned that it's becoming 'Ubuntu first and we'll get to the rest of the community if we can' type of deal. You may very well be shooting yourself in the foot.