it takes longer than 3 seconds to see whether a new poster is consistently an idiot and worthy of being removed. once you determine they need to be ignored, then it takes 3 seconds.
Our beloved ET Dictator makes money with the rating system, because it is registers as extra hits on the website. Why would he want to give that up?
There is a delay for the Stormfront army to wake up once they get the alert, drink a beer or two, then mosey over to ET to click the ratings and vote.