Of course I am. If a new release of Gnome broke some code of yours (that sticks to documented APIs and worked fine on the previous release), you would file a bug, regardless of the fact you could have downloaded and built everything from their version control on a daily basis to test, even automatically. Why should we treat Microsoft any different? Even if I detected the problem in the first public alpha, I would file a bug.
If the code sticks to the API rules and a new release of the OS broke it, it's the OS that's buggy, not your code. If the OS maker doesn't fix the bug using the "you should have tested" excuse I question how much it respects its users and developers.
I understand he meant that nobody is scared of Microsoft anymore. I guess the question I have is, is there a company that exists that everybody IS scared of? No. So I rather chalk it up to a sign of the times.
As recently as last year I was reasonably scared of Apple because they appeared to be accumulating a market power that was transforming the industry itself into something I didn't like.
Fortunately, however, Google came to the rescue with Android and I'm now far more relaxed about it.
A lot of people claim to be scared of Google though ...