Wikipedia's editors (or, perhaps more accurately, humanity) have a bias in thinking details in the present are more important than details in the past.
While I'm sure a bias towards the present is part of the problem, there's also the simple fact that it's easy to write about things plenty of other people are writing about, and about which details are plentiful. Many of the things Wikipedia is missing, but really should have if it wants to call itself an encyclopaedia with any pretense at seriousness are obscure, and their details locked away in obscurity. (As a consequence of this, many of those things Wikipedia does have articles about are couched in the language of someone who already understands the topic, mitigating their utility to those who don't.)
All that said, the article on the Republic of Ragusa was far better and longer than I'd have expected, given its use as your counter-point.
That's very amusing, because the exact opposite bias can be found in traditional encyclopedias:
> The other day I read a dozen thousand words about Assyrian archeology in my DVD copy of Encyclopedia Britannica, but when I wanted to read about the Xbox 360, there wasn't even a single entry, so I gave up.
> Wikipedia's editors (or, perhaps more accurately, humanity) have a bias in thinking details in the present are more important than details in the past.
You make a great point, and I think that ties into how one defines 'important information'. Specs/prices/etc.etc. about the XBOX 360 are all but ubiquitous on the internet; does this mean that, because they're more common, they're more important and thus should be added to Wikipedia? Or do stricter filters need to be placed on more common knowledge/data?
The article for the XBOX 360: http://en.wikipedia.org/wiki/XBOX_360
The article for the Republic of Ragusa: http://en.wikipedia.org/wiki/Republic_of_Ragusa
Wikipedia's editors (or, perhaps more accurately, humanity) have a bias in thinking details in the present are more important than details in the past.