Then, by all means, fix the search functionality.

Patches welcome.

One should realize that titles are just, uhm, titles. They are not a list of keywords to an index.

In fact, quite the opposite is true. The node titles are keyword lists (in addition to being plain titles). Understanding this fact should go a long way towards understanding why site policy regarding titles is the way it is. Which is why your protestation that:

it's certainly not true that any one word subject line doesn't describe the node accurately.

is entirely beside the point. Good titles should be able to serve as abstracts of the node or thread (just as Mr. Lee suggests, elsewhere in this thread). "HaXml", like most one-word titles, fails miserably in this, because it doesn't tell me anything about the node — other than, perhaps, that the word "HaXml" also appears in the node body. The title ought, at the very least, to mention "Haskell", don't you think?

In addition, I believe that, as a general rule, node titles which look like root node titles (i.e. there's no "Re:" in front) should only be used on nodes that look like root nodes. One recent breach of this standard is Shorter code. Such a title conveys zero information about the node's content. In fact, one must resort not only to ancestor nodes in that thread to discover the context, but to other non-ancestor nodes in the thread. That's a crappy retitling indeed... and it doesn't even suffer from the "one-word title" disease. "HaXml" is that much worse, because it does.