Question: How are rational egoism or laissez-faire capitalism more objective than rational altruism or communism?
Answer: To be objective means to be based on features of reality that can be observed or deduced by anyone. Scientific experiments are objective, for example, because they are explorations of nature that can be replicated by other scientists. Pronouncements from God are not objective, because only the person who claims to have received the message has the evidence, and the rest of us must take his or her word. To answer your question, then, it must be shown that rational egoism and laissez-faire capitalism are more closely related to reality that rational altruism and communism.
Rationality needs to be rooted in reality. Ayn Rand once pointed out that our success in this world is directly proportional to our rationality. For example, you cannot build a skyscraper or communications network or even plant crops in a straight line without reference to reality. You can sacrifice virgins on an altar without rationality, but you cannot build the altar. God may tell you to sacrifice virgins but God will not tell you how to construct the means for doing so. Therefore, to be rational is to be objective.
Egoism commonly means that the motive and valid end of action is self-interest (Webster's). Objectivists regard egoism in much this way, in that people are entitled to and should have their own happiness as their primary motive and end. To be a rational egoist is to follow a plan of life that promotes your own happiness. It is important to note that happiness here is taken to mean fulfillment through rational action, not hedonism or the pleasure of the moment.
Altruism, on the contrary, requires each individual to live for the sake of the group, trusting that his or her own needs will be provided for. Altruism typically holds that individual fulfillment occurs through service to others; most religions openly state this, and it is a driving force in socialism and communism, too. Altruism places the survival of the group ahead of the survival of any individual, and this is what enables the repression and slaughter common to extremely altruistic societies. Stalin is generally regarded to have had killed more people than Hitler, and both did it in the name of the group.
The danger of altruism is less obvious in freer countries like the United States, but it is still a powerful force that is a frequent justification for restricting individual rights. It is very typical for city councils to regulate, to a very fine degree, the uses that may be made of every piece of property in the city, all in the name of protecting the citizens. Because altruism puts the group first, it is much easier to pass restrictive laws, and this results in "creeping regulation," where the government passes progressively more intrusive legislation to protect "society." Many environmental laws have altruism as their base justification: they restrict our enjoyment of the earth so that future generations will receive the same planet as we do.
This creeping regulation is ultimately stifling of individual initiative and quality of life for the majority. The same "creep" occurs in totalitarian countries. The USSR passed so many laws that it became illegal to do almost everything, and thus possible to denounce and arrest someone for almost anything. Even in post-Communist Russia it is impossible to do business legally. We see the same thing happening in the United States: there are more laws than any of us can reasonably be expected to know. In most cities, for example, you cannot do any hairdressing without a special license. This is ostensibly to "protect the public," but in reality makes it more difficult for people to work their way out of poverty. It also protects vested interests, which includes not only those who are already hairdressers, but also the government itself. After all, the more regulations there are to be enforced, the more government is needed.
To be a rational egoist is simply to live in accord with human nature. We are all independent reasoning organisms, and the only life we live or happiness we directly enjoy is our own. This does not mean that we cannot also be interested in the well-being of others, and it certainly does not give us the right to stand in the way of their pursuit of happiness. That rational egoism is human nature explains the failure of altruistic systems like communism. David Schmidtz, a philosopher at the University of Arizona, has pointed out that it does not make sense to design political systems that do not accord with human nature, and this is exactly what altruistic systems do.
Laissez-fare capitalism has its roots in human nature, or reality.
Laissez-faire capitalism is simply the economic expression of rational egoism, and as such has its roots in human nature, or reality. Capitalism simply allows people to pursue their rational self-interest. This allows us to say that capitalism is objectively superior to communism. Again, if a system accords with human nature, we would expect to see it succeed, and capitalism certainly seems to be doing so. Capitalism has been around much longer than communism, and is no danger of collapsing the way communism did. Capitalism has created too many people with a vested interest in maintaining the system, which is to say, that it fills their needs and so they want to keep it. It is not democracy that prevents wars between countries (Hitler was elected), but mutual trade. People want to protect their own interests, and when you trade with someone in another country, that means that you must also protect their interests.
Capitalism has also created the fantastic wealth of our world. This is generally conceded even by Marxists! We have more time, more money, live longer, and are healthier, and this is due to capitalism. Simply contrast the living conditions of capitalist nations with those of current and former communist countries. Capitalism allows individuals to pursue their own happiness in their own way. As such, it promotes individual responsibility.
To sum up, something is objective to the extent that it relates to reality, and thus can be verified by others. Human nature is rationally egoistic, not altruistic, and this nature is best served by laissez-faire capitalism. Thus, we say that rational egoism and capitalism are more objective than systems less well grounded in human nature.
Some suggested readings:
Leonard Peikoff, Objectivism: The Philosophy of Ayn Rand
Ayn Rand , The Virtue of Selfishness
William R Thomas, Radical for Capitalism