This reminds me of one of the video's when the Sylvari were introduced... They kept saying, 'you haven't seen everything fantasy has to offer', but then they just kept showing 'plant people'... Because really, that's new...
I have never before heard of Dryads... Or the like... And sure, you can claim that Dryads and Sylvari are different, but they're still fruits (apples vs oranges)...
As for the OP... They were the newest race added... A lot of people have short memories, and the most recent flashy addition wins nine times out of nine and a little bit ; )
-Alamar