In a never-ending game, there are finite 'things to do' and youre bound to repeat them eventually. Over time, you repeat them repeatedly. Boredom ensues.
So my honest, constructive question to the vocally bored masses of 50's: How are you wanting to spend your time, and how is this game not fulfilling that? (Or if you're 50 and happy, what are you happily doing?)
Going a step further, is it any different with other MMO endgames?