What I can't fathom are people who speak of having "done all the DEs" in a zone so they have no reason to go back. I run into DEs I've never seen before even in zones in which I have 100% map completion on another character. I begin to question whether there is one single GW2 player who has actually done ALL the DEs in even one zone, including all those that are triggered by speaking to the right NPC or finding the right object. Even if you could find one player like that, could you really find 100? 1000?
I also have to question whether most players have actually done even most of the prominent DE in the O2OMs, as Fluffball so nicely put it. My first level 80 got to Straits of Devastation when the game was about a month old and there was still a good number of people around. Since then I've usually had at least one character hanging out in Ft. Trinity to do a quick daily farm in the area, and I often finish off my dailies with all the small soloable events there. In all that time I have never once seen anyone doing anything about the bone ship when it appears off of Half Circle Cove, though I've gotten killed a number of times trying to do it alone. Did every other player in the game just happen to get there and do it in less than a month? Or are most people just skipping DEs that they don't think will be profitable enough?
Even back in September people were not doing most of the invasion event chains, but there was a permanent population defending Lone Post. (Even that's gone now, and Lone Post is very lonely indeed.) Am I supposed to believe that only one month into the game, 99% of the players had already done all the DE in that zone and left only some farmers behind? Somehow I don't think so.
There is some other reason why the Priory Explorers will be trapped in the Risen Clams for eternity and that crashed helicopter in the swamp will never get back in the air. Any way I look at it, it's clear that DEs in all zones are not languishing because everyone has already done them. Perhaps many of them are just not appealing to enough players for some reason. Perhaps players just feel too much pressure to move on and don't have the patience to wait around for rarer events, search for the triggers for those under player control, or hang around until they've seen all of a chain. Whatever the reason, I suspect that a majority of DEs in the game have never been done by a majority of the players and the content has been wasted since day one. Which strikes me as a real shame.