there has always been tension in the FOSS community between those who are willing to make compromises in order to provide needed functionality now and those who will do without the functionality until it's free.
Mark has clearly placed himself (and Ubuntu) in the camp of those willing to so things that the other camp isn't willing to do in order to provide functionality now. He is far from being alone in that camp (Linus is another vocal member of that camp) and his description of the other camp as being 'ideologues' is not unexpected (or, in my mind particularly inappropriate, what would)
the problem that he talks about where companies start to open up and get hammered for what they haven't opened yet rather than thanked for what they have opened is a serious problem
I also don't think that anyone disagrees with the '80% complete' problem that he describes.
the need or lack thereof for contributor agreements is a matter where there is a lot more disagreement. It's good that he isn't happy with the current Cannonical agreement, I don't think anyone is and the big thing that he needs to do is to make it clear what he is trying to do with this agreement and re-write the agreement to provide the appropriate guidelines (it may be good enough to add guarantees that the software will always be available under a particular license or class of license in addition to any proprietary licenses that are granted)
I do think that it's a good thing that Mark had decided that it's acceptable for Cannonical to sign contributer agreements when submitting patches to other projects , as that should reduce the friction involved.
but as long as the FSF is requiring contributor agreements, many of the more vocal people really have a hard time arguing that the concept of a contributor agreement is evil.