Since the release of naxx it became clear that "BiS" lists aren't important and are really heavy personal goals that players put for themselves, but the problem is - it comes from raiding, and to raid you need other players who also compete against you to get said gear. The only "BiS" list player should care about (and by that i mean that it's not a personal goal that you put for your enjoyment, but a requirement if you want to be competitive and, you know, valuable) is a pre-raid BiS list.
Some people here compare BiS list to be some sort of an end goal of the game, which wasn't the case at all. It was a personal goal, you still can make your own goals for the game.