One way to think of it is: when you wager on Intrade because you think the price is inaccurate, are you more like

1. a pundit being paid to bloviate, cheerlead, and mislead ordinary people (one thinks of the more right-wing writers who up until election day were confidently predicting an Obama victory and trashing Silver or polls in general), who even if one's motives are pure still contribute to the blinding white noise of media and is wasting people's time and leaving behind false ideas, delusions, questionable datapoints etc.
2. or a polling firm who, while motivated by profit, still seeks to add in real data to the race and which profit is ethically justifiable by the value-added of better data about how the race is going