I also didnt think of this post to be insulting at all, everything they say atleast seems to be reasonable.
But it is weird that they dedicate their time to say something like this and not try to please the community that is on the verge of quitting.
I'd say community is quite angry atm, but saying on verge of quitting 5 days before "big balance patch" is inaccurate to say the least.
Moreover, there is always a time to write something about company policy and the intended use of the product they have developed, I mean, its not like a dev or balance teams are writing that down, that is the job of product directors and community managers.