I kind of want to ask 'What's wrong with world 7?' but I'd probably just get a big spiel with a lot of exaggerated statistics, extrapolated from the opinions of one group that comprises less than 1% of the userbase, combined with some wildly inaccurate generalizations that only apply to 1% of the game world, so it doesn't really seem worth doing... (You know World 7 is really big, and almost everything in it is mutable, right?)
Anyway, strictly speaking, Loftar didn't rule out a world reset of the current game world and server, he just said that Hafen comes first. If I really wanted to, I'd read into that that Hafen development might be delayed after release, in which case the current world might be reset... although I can't imagine why that would be if they were still focused on developing Hafen. The reason why world resets used to be more frequent was because new stuff was being added and things were being changed, not just 'because the world has been around for a long time'.