This site was set up by Douglas Noel Adams (who was proud to have the initials DNA) and his friends (calling themselves "The Digital Village Ltd") as a real-life incarnation of a fictional book that was at the centre of a series of stories he wrote. (In various, often conflicting, forms).
That's right, h2g2 *is* the Hitch-Hiker's Guide to the Galaxy, not a discussion *about* the Hitch-Hiker's Guide to the Galaxy. It is intended as a "live, voluminous, self-organising, and individually responsive" (Douglas' words, on Welcome-DNA) guide to Life, the Universe, and Everything. Nothing more, nothing less. It has always been made clear that it is *not* intended as a Douglas Adams fan-site - it is far, far, more than that.
Building the site into a community has always been seen as, basically, a good thing - "If h2g2 were a peach - and we very much hope that it is - then the Guide is the stone at the middle and the Community is the fleshy bit. Or something like that..." That is to say, it's not supposed to be like the editing room of an encyclopedia - it's far, far, more than that, too.
The original site, h2g2.com, was run on software called Llama, then software called Ripley. However, when the original management realised they were going to run out of money, the BBC took over the site - including all current content, and all technology. Part of their motive for this was that they could generalise the technology used to run h2g2 to run other sites as well. Eventually, this generalisation required such a rewrite of the software that they needed a new name, and they settled on DNA - as a homage to Douglas, who had passed away shortly before.
So, am I going to have an opinion or am I just going to give you all a history lesson? [Well, both...] Personally, I see nothing wrong with people using the site for random chat - they are helping to build a community, and a network of information and helpfulness, or just plain friendliness. The site has evolved a lot over time, and individual users' usage also varies over time. I share the concerns of those who feel the central Guide (the stone of the peach) is becoming too small a proportion of the whole, but maybe we just need better ways of tapping the knowledge of the Community. I also share the interest of those who would like to talk more about the ouevre of a certain writer named Douglas Adams, but it should be remembered that this is no more or less important to the guide than, well, a game of Mornington Crescent.
To sum up, here's another quote from Douglas: "And when you write in something as simple as 'The coffee here is lousy!' the Guide will know exactly what to do with that information and where to put it. And if you see, a few seconds later, a note which says 'Yes, but the cheesecake is good' it might be worth looking round the other tables to see who you've just made contact with."