All of these these social media and free image hosting sites do have a benefit, but also a limitation. When a photographer starts their own "clunky website", they are free to define the licensing/usage terms of their images however they see fit.
Under Facebook, Tumbler, Flickr, etc, the user is at the mercy of someone else's rules and regulations and must decide a go/no-go as to whether or not to sign up for the latest internet fad.
Good point.

I guess the thing that appeals to me about the Tumblrs, not to mention the LiveBooks and other "pre-rolled, easily customized, minimalistic" sites is that they are almost always so much better user interfaces than the lone site kludged together with Dreamweaver or worse, the big $$$$ Flash site that the bigger photographers impose on us. Nothing says you can't roll your own but follow them as a model.