communist manifesto

According to this writing one of reasons that capitalism is not a good system to due to the Bourgeois, who hire workers, the proletariat to cultivate or produce their capital. Marx's communism would eliminate the Bourgeois and make the private property public to allow the greater distribution of wealth among the proletariat. My questiuon is that wont corruption eliminate this re-distrubution of wealth because the greed of the few eliminate this equality? Does Marx belief people are naturally good enough for this system to support itself? I don't think this type of society will function because people will always want more.