Brent, I don't think anyone would argue that you're not technically correct. The inventor himself has this sort of naive well-intentioned idea that the thing will be used for exactly what you say, giving voices to the voiceless, etc. Hell, I agree with you that they were right to blow off the marketing guy in that interview due to his obliviousness of an major evolving marketing tool.
The problem is that if Klout really does become widespread, there's a very strong chance that people will not think of it as "A marketing tool". They're going to think of it as a quantification of how cool and important they are. It's like that snarky .jpg of the Orwell quote warning against hypersimplification with a facebook "like" button next to it. With such open-ended things as social media platforms, it doesn't matter what they're supposed to do, it matters what people make out of them.
In fact, Facebook or Twitter are a great example. Those things already have problems with people who think that the number of friends or followers you have is equal to some kind of win-at-life score (which is just a public quantification of something we all remember from school anyway). The thing is, Facebook, Twitter, and the like nominally have some other useful purpose as their main function; the Pokemon version of social interaction is just a side-effect. But the thing is, that nonsense is Klout's whole reason to exist.
So yeah, sure, it can be used for good. And I expect that if it takes off it will be sometimes. But I think the mundane day-to-day effect will be a much more negative one overall, with people trying (and mostly failing) to game their "cool on the internets" scores like they were min-maxing a shitty D&D character.