I've been going through the early issues of The Dragon in another thread, issue by issue. I think a lot of this is just looking back through a lens of nostalgia.
"Excellent Fiction" - Yes, clearly there was that. There was just as much poor fiction, too.
"The writing was rich and dense and assumed a highly educated audience" - sometimes. Just as often it was sophomoric and written to the lowest common denominator. Take a look at Len Lakofka's first credited article in The Dragon, it was incredibly sexist (I was really suprised when I read it recently that they would publish that drivel) and not worthy of his later writing.
The current issues certainly assume an educated audience in some articles. Look at the recent Demonomicon articles. These would easily slide alongside any of the quality articles of yesteryear and hold their own.
"Sometimes there would be 2 or 3 concise articles on a single page!" - It was pretty easy to do that when you could put a chart in the magazine and call it an article. Once in a while you might add a paragraph of explanation. Wow, what great writing!
Yes, The Dragon had some great stuff. Yes, the paradigm of the magazine was very different. Today it has to compete with the internet. A lot of the things that they published in those days would not fly today (the "charticles" is the obvious example), or you can easily get free with a quick search of the web. However, a lot of what was there in the old days is still floating around.