Greed is a behavior learned through evolution (hence it's written in our genes) due to our world having limited resources. It might be, from a metaphorical point of view, that it's a sympthom of repression... but greed is as natural, innate, as it gets, because that "repression" has been with us for so long that it's hardwired into our genes. Through culture we can overcome it, yes... just barely, though.
---------- Post added 2012-12-05 at 05:27 PM ----------
Do you understand that the Soviet Union didn't work against greed? In fact, it worked in a similar way to many other countries that were/are run by oligarchies who own all the resorts of power (not unlike how Russia still works even now). Those oligarchies were very greedy, and probably they were objectivist (certainly their morality was very close to it).
The Soviet Union collapsed because of the inefficiencies of the top-down approach when there are now down-top means of control. The Soviet Union collapsed because of the rampant corruption, not because of trying to enforce the disappearance of greed.