Hah, well, I was surprised to get even FOUR upvotes. Good to know, I guess...?
Anyways, I had meant to bring up HN as more of an example of a bubble--both because it has an exclusive attitude (which is exemplified in part by a non-zero barrier to entry) as well as a self-selecting user base.
I'll give you another one. Not sure I agree completely though. Most popular communities do deteriorate in the quality of the discussion over time (even this one, spend some time here, you'll see pretty quickly).
The truth is I think it is important for people to "choose" to be real consumers of the services (yes even content services) they feel provide value to them. Otherwise what's the incentive to do anything but pander to the masses to get "eyeballs". Most importantly, there is clearly room for both models, what your post suggests is a false dichotomy.
Anyways, I had meant to bring up HN as more of an example of a bubble--both because it has an exclusive attitude (which is exemplified in part by a non-zero barrier to entry) as well as a self-selecting user base.