Excerpts From the Article:
Crowds are not wise. Crowds are great as part of a statistical process to determine the perceived numerical value of something that can be quantified. A crowd, in other words, is a decent calculator of subjective quantity, but still just a calculator. You can show a crowd of 200 people a jar filled with jelly beans and ask each how many jelly beans are in the jar. Then you can take the average and that would be the closest value to the actual number of jelly beans.
I think, the issues raised are very genuine, the current democratic form of Digg is certainly much better than the autocratic nature of slashdot but still it needs to evolve a lot.