Ever played any online game with ingame currency? There are no pricetags in dollars. Well at least used to in Diablo III that is possible too. The difference here is item prices in dollar follow their ingame gold value not verse visa.
That's the point I'm trying to make if bitcoin started as a trading tool for something valuable but not necessarily costly (for example game items or pictures) it would have evolved very differently. It's already too late for that since we have almost half of all bitcoins valued in dollar instead of something fundamental.