They are not stringing anyone along theve had so many games under development since skyrim released and they also know how many of there fans are still patiently waiting for the next Elder scrolls and want to make sure they do everything right by the gamers and still make it more than skyrim was (which are pretty big shoes to fill). If they didn't care about there games and how they play and how they grow in the gaming community they wouldn't be spending so much time on it but with everything going on they basically feel they HAVE to get this right or they will lose fans and they dont want that.
Dont be so quick to count the next game of the series out just yet. Have some patience and this game might just be better than its successful predecessor