I hadn't seen the post you mentioned, but the whole thing was so dripping in arrogance and a complete disdain for Wikipedia and its international users and contributors it is begging to get panned.
Basically, it is the original post that is not constructive to the point of being hostile. There is very little "polite" about it.
Maybe it should have been ignored rather than reacted to, but this kind of thing would provoke a negative response anywhere.
Also, I suspect the whole scenario of arrogant designers presenting a design that completely ignores the needs and identity of the client and the audience, interspersed with arrogant statement declaring their own superiority is not entirely unfamiliar to many here. At least my first reaction was "oh great, that again".
This is not a way to start an friendly open discussion or get constructive criticism. It's a provocation, which is also a perfectly valid way to start a debate, but it does set the tone.