It keeps coming back to two facts:
(1) External sites are going to criticize Wikipedia, and (2) Those sites aren't going to bind themselves to WIkipedia's rules.
It seems to me that almost anyone criticizing Wikipedia from outside is going to come upon cases where they will feel compelled to "out" some editor. The principle that real-life identity does not matter isn't generally accepted (in my opinion, because it isn't true), and situations will arise where critics will feel the need to demonstrate that it isn't true by unmasking an editor (see "Essjay controversy"). Those critics are also likely to have different notions of how to "decorously" discuss matters.
As a general principle Wikipedians are going to want to refer to such criticisms in discussion about how to improve Wikipedia. The erased link that brought me into this was made in exactly such a context. In this wise we seem to have a meta-policy here that Wikipedia can only be criticized on its own terms, which strikes me as a lame principle. As far as WR is concerned, a lot of what is said is rude, immature, and frankly incoherent. Nonetheless I have found it worthwhile to engage them. Anyone who has read TNH's commentary for long knows that it gets pretty pungent.
I see that there is now a better attempt being made to define what an attack site is. I'm not sure that this is going to work, because the threshold for what is an attack is being set quite low. But somehow it's going to be necessary to distinguish between criticism of Wikipedia and "attacks".