Yes, I think I replied to that branch of the comments as well.
And again: No, they are not immune to criticism, they have just set up a way in which criticism is handled in a particular manner, ie. channeled into discussions or in hands-on fixing. If you don't use either, you don't need to act surprised that they don't appreciate your criticism.
Don't really see how you came to this conclusion. The very bug that's linked in this story was filed in the proper forum more than half a decade ago (i.e. it's a counter-evidence to your assertion).
And again: No, they are not immune to criticism, they have just set up a way in which criticism is handled in a particular manner, ie. channeled into discussions or in hands-on fixing. If you don't use either, you don't need to act surprised that they don't appreciate your criticism.