Capitalism depends on the selfishness of the individual and their ability to extract the highest value with the lowest cost. Communism depends heavily if not fully on ethics. We are definitely not an ethical people. So you are correct the former is more preferable to the latter, because it's easier to implement. You cannot depend on ethics unless those ethics create the highest value at the lowest cost for the individual. So the key would be to make restrictions that inspire the ethical approach over cutting corners. If that is possible, then whichever system is used, they are more likely to be better than the alternative.