Comment
I have stayed away from this discussion for a couple of days, minded to retire from Wikipedia.  I'll postpone that idea a while.  There is an important issue here.

Does anyone wonder why this page suddenly became the focus of attention?  From 2003 until July 17 2011 the length of this talk page grew to 17,726 bytes.  Since August 29 it has grown by 74,997 bytes (before this post).  Meanwhile the List of castles in Wales remains rather neglected, and there is no sign of new individual county pages of castles in England getting extra attention.

A glance up this talk page to see what was written here before August 29 2011 will reveal unfailingly polite discussion.  Here is a sample of what has been written recently:

"The professional attitude towards the current article has been lost to ego...  As this is a shameful topic opened by Paravane...  Paravane, you are ignorant and I'm tired of your possessive behaviour, against ownership guidelines... Clearly you are not competent in terms of reasonably developing an article to support the wider community... This article is a sham - a bloated mess, with weak keys, many images, and shoddy management. You have done nothing in terms of AGF of those making edits, or suggestions and continue to pursue your own mis-guided approach... As for FLC - they wouldn't touch this with a barge pole... splitting... removes the current possessive ownership attitudes which haunt the article..."

Two points in particular deserve consideration:
Some editors, faced with what appears very plainly to be a personal campaign against them, will opt to retire from Wikipedia, and especially if personal attacks are seen to achieve their purpose.
If reason is not the sole - or even the principal - mechanism of advancing a campaign, it cannot be depended upon that reason will ever be sufficient to counter it.  If the campaign is obsessive, every line of reasoning will be dismissed by every possible means, and the campaign may be carried for no better reason than its opponents weary of arguing. 
A practice of ignoring the breakdown of mutual respect, as a basis for cooperation in the community, can hardly fail to be damaging to Wikipedia.