Because for most who have held out hope there's no other way to look at it. I understand raiders are a low percentage of the population and it's high cost content. I still believe it adds value to the game for more than just the >10% crowd. I also believe it is a self-fulfilling prophesy of fewer people run raid/instance content because it hasn't been released with HD (Erebor was very disappointing), and without new traditional content there will be many who never experience it at all in lotro. There will be others who leave because of its lack, or come back for brief moments rather than months. To me it's rather a sad statement. I didn't say it was new, but when people see words like "near future" and "foreseeable future" it leaves hope for the "later future". Give a man hope and he hangs onto that, regardless of if it's reasonable. I think for a lot of folks this popped the last hope bubble they had.
Many foreclose because at some point they need closure.