What really made the great was that the internet in itself was in its infancy, and there were only a handful of MMO's like EQ, UO, and that Mu thing. RP'ing was massive and unmatchable in UO - WoW and Daoc put together couldn't even come close to the RP guilds that inhabited the lands - they made UO fullstop.
I think this sums up a lot about the path of MMOs over the last 12 years.
When UO arrived on the scene and blew so many people away, the internet and playing online was a pricey expensive affair. This meant that it attracted a much different userbase than today. That userbase had different personalities and different aims than many today.
This for me was the golden age of MMOs and indeed online gaming in general. It was very niche, you were ostensibly weird, uncool and nerdy. Over the years, online access has become very cheap and online gaming has become widespread and isnt really viewed as uncool any more, some might say quite the opposite. The result of the unwashed masses spreading forth online has meant an enormous dilution of the sorts of people who played UO in those early days and a larger expansion of the bickering, argumentative, insulting, "I pwn" crowd who at times seem to lack the social graces to hold a conversation with their reflection in a mirror , let alone with an individual from somewhere else on the globe.
UO was simply the greatest game I have played of any genre, online or offline. Sadly I dont think we will ever see its like again, not entirely due to the various devs but in part due to the changed userbase.
On a side note regarding Stratics, I remember being interviewed by Stratics during my time as leader of a well known player run town on Catskills. Bet that interview has long since disappeared from the Stratics archives by now
EDIT : hehehe, no trace of the interview, but managed to find an entry about the town still
http://uo.stratics.com/shard/Catskills/ca_KinshipHall.shtml