Pew overstating changes in blogging/internet behavior?

The Pew Research Center’s Internet & American Life Project has released new findings that they claim show that,
“… young people are losing interest in long-form blogging, as their communication habits have become increasingly brief, and mobile.”
If this is accurate, I would think this a negative development because I think of “long-form blogging” as usually involving some measure of analytical and critical thinking and reflection, which are important skills for participation in information & knowledge societies. However, I’m not convinced that the turn from using blogging sites to using short-form communication sites (ex. twitter, facebook) is as much of a change as the researchers suggest. But, we can’t be sure that this is the case because researchers’ tendency to focus on the technology used, instead of what it’s actually being used for, limits our knowledge.
The big question here is, were young people actually using blogging sites to “long-form blog” or were they using them to “short-form blog”? I think, in fact, that a large number of young people probably used blogging sites to do exactly what the short-form sites are made to do. The transition doesn’t necessarily suggest a change in behavior. Regrettably, I don’t have data to back this up, but it’s consistent with what I’ve seen over many years of casually traversing blogospheres.
The researchers’ claims reveal assumptions based on a deterministic view of technology. It’s sort of like assuming that if someone has a hammer, they can build you a house (okay, that might be a little over the top, but you get the idea). This deterministic thinking about technology is still remarkably prevalent and something we have to turn around if we are to truly expand our knowledge about how individuals interact with, and are affected by, technology.