Yes, Instagram has some value, but it's in the users and the eye of that particular person that you enjoy. The photographs themselves are rarely anything of note.
I do think it's unfair to lump these companies. Hipstamatic is just selling an app. Even if the community turns into nothing, they sold quite a few apps at $2. Most of these companies though have nothing to sell and little value to provide. They are just hoping for some angel to bail them out until the inevitable Google buyout.
And stop reading TechCrunch already.