People want the big E-tickets. It's just like regional amusement parks...always having to build bigger and better things to keep the people coming back.
As for me, I'd much rather have Mystic Manor or Beastly Kingdom over Avatarland or Star Wars land...but I guess I'm in the minority.
For me it depends on the park...I don't think DAK or DHS need e-tickets, I think they need a fully fleshed out land/area that has multiple family things to do like FLE. I think that MK needed an E-ticket more than it needed an FLE type expansion. EPCOT needs a lot of loving/maintaining/upgrading. For me, Mystic Manor would count as an e-ticket. I don't think of e-tickets as being just thrill rides, but maybe I'm in the minority.