Edit: Also, a comment I wrote a while ago with some more thoughts and information on fidelity bonds: https://news.ycombinator.com/item?id=6048650 (starting on the 3rd paragraph)
Being easily cynical, I will say that those who currently own Bitcoins are those who would make a buck if it was adopted, so it's not surprising to see that kind of idea there. But that's just me being cynical.
Anything that increases adoption increases demand for bitcoin and benefits current owners-participants. Cynical is a cynical way of describing this. Interest doesn't necessarily mean sociopathic. It's good for people to have an interest in making bitcoin successful.
Our current sensitivity to financial bubbles is confusing here. Currencies are basically always bubbles. They have value only because and to the extent that people believe they will have value in the future. To make a new currency, you need to make a bubble.
IMO, what bitcoin needs is exactly something like this: uses as a medium of exchange. A lot of the current interest/value is centered around bitcoin as a value store, if that's what we want to call the current speculative investing. To really make an impact as a currency, people need to be exchanging bitcoin for goods & services.