Well, if you mean what I'll call pop-communists (those similar to teenage anarchists and the nihilists Arkady and Bazarov from the Turgenev novel Fathers and Sons; no offense to any present), it's fairly easy to see.  Elitists basically say that they are above others in their society; sterotypically because of wealth.  You might as well ask why socialists and communists hate capitalist pigs ;-)