I can't help but wonder if perhaps the perceived failings in Microsoft products could be the result of an internal attitude towards criticism that is similar to the attitude towards criticism that you are expressing here.
Does Microsoft have an internal culture that discourages criticism, which results in criticism from the outside world catching Microsoft employees by surprise?
No, there is plenty of criticism internally. It's just not criticism about the same sort of thing. It's more political than technical/product.
Frankly, I don't think my friends who work on Windows Phone realize that it's a failure. When I last talked to former coworkers from Windows 8, they didn't think it was a failure.
I doubt it, the surface team actually does regular AMA's after a product launches. They do listen to criticisms and manage to correct most of them in the next iteration. If you watched the keynote event, Panay talks about it, especially in regards to the trackpad issues. Not to mention the usual flurry of "M$" and "Who uses bing?" comments they have to deal with.
Does Microsoft have an internal culture that discourages criticism, which results in criticism from the outside world catching Microsoft employees by surprise?