It amazes me that the average user seems to have absolutely no idea what Communism is.

The self-checkout systems have their niche, I only use them when I have a few items, but with advancing computer technology they can become better. As for Walmart, they would require more customer service supervisors and computer technicians the more self-checkouts they use (until artificial intelligence, of course.) They can use their cashiers to work as sales reps and stockers. I do have to admit, at least, at my walmart cashiers have the highest shortage and the more bargaining power, but if a single few cashiers call off for a day, it can affect profitability so much more than if other employees call off, and it makes a lot of sense why Walmart chooses backup services, like self-checkout. 

I view your next paragraph as an issue of cronyism/mercantilism/corporatism/fascism, the merger of big business and government. Notice that it is the local government or the U.S government having an integral role in exploiting people. Free-markets, or laissez-faire markets as some call them, whether they will have a socialist (egalitarian) structure or a capitalist (hierarchial) structure would not have this. The nordic countries are probably the most social democratic countries in the world, but they also happen to have some of the freest markets (excluding Norway), for example. This is what contributes to most of their success. Recently I've been reading a lot about left-wing market anarchism, and I've gathered that to a lot of left-winged individuals : anarchists or not, "capitalism" doesn't mean "free-market" economies as it does for right-wingers (right-libertarians mostly.) For these people, capitalism means the mixed-economic system present during Marx's time in which workers were exploited by industrialists. I think that is where a lot of the differences between left and right wing occur, the definition of "capitalism." This is of course talking about propertarians (people who believe in the private ownership of capital) on the left and right only: excluding syndicalists and communists who don't believe in private-property rights. 

I don't believe colonialism is the only contribution, though. I talk about it a lot, but look at Hong Kong. It was a British colony that succeeded by not limiting trade through tariffs and regulations. The people in power were the local population. Even today, as an autonomal government in China (one of the least free markets in the world) Hong Kong has great success. This wasn't based on exploitation, but on voluntary interactions, peace, and cooperation. 

I think Communism is nice when you write it on an utopian essay, but unfeasible on the real world given that resources are always limited.

I was under the impression that NYC has banned all food donations, including to homeless shelters and food banks.

The main issue with communism is human drive. What motivates you to go to work every day? What motivates you to do a good job? What motivates you to get a higher education?

The principles behind communism sounds great, everyone deserves equal treatment. Janitors are just as important as doctors to have a functioning society, so why pay them differently? However it is easy to see right where this breaks down, who is going to go through 8 years of med school so they can work long hours every day while being oncall all the time when they can just get a job right out of high school that pays exactly the same with the exact same benifits?

The greater good of your overall society is (sadly) not enough of a motivator for most people, and thus communism breaks down.

The reason capitolism works (better than any other system tried on a scaleable population in my opinion) is that it supposes that a person is naturally greedy/competative. People naturally want to get ahead of eachother and capitalism rewards that behavior.

Broken and incomplete like any other ideology out there. I prefer it to capitalism though.

The USSR had more doctors per capita than any capitalist nation. This is because the tuition that medical students have to pay is a far bigger barrier than being "poorly" compensated for their contribution to society. Why do we just take random guesses as to why "communist" states fail?

Tell us then.

And yet, for some reason, Cuba - which is clearly the most communistic country that still exists, even if it's not a true communism either - has about the highest percentage of doctors in the whole world, being only slightly beaten by Monaco and Qatar, two of the richest countries of the world. Despite their doctors being paid just about 15$ per month, pretty much like everyone else. How do explain that, when it seems to clearly contradict your argument?

I think that one of the things you ignore is that a higher salary isn't the only benefit that counts for people when choosing a profession. Doctors are often about the most-respected people in society. This probably also has an effect on women - cuban woman will probably also tend to prefer doctors over janitors. And when you're forced to do your job for several decades, there's also other things that will make one job seem more attractive than other jobs. Many people will probably consider a janitor job more boring, and doctors will probably tend to feel their work being valued more. And so on...

And studying in Cuba is free (just like health care, school etc.), so it's simply not like in some other countries, where becoming a doctor can be so extremely expensive that it only makes sense if you're earning a lot afterwards.

But anyway, where does communism even necessarily require everyone to earn absolutely the same? I've so often heard that argument, but I've never heard why. I mean, even if "who would become a doctor if he could become a janitor instead and earn the same?" really was an eternal fact, one could easily think of a compromise: Make the best-earning job earn, say, twice as much as the lowest-paying job. That should already drive people's motivation. The exact ratio is totally up to debate, of course, I'm just trying to point out that it would be easy to counter certain problems that communism is said to have by making small compromises.

Btw, I doubt that some of the conclusions you make about the "human nature" are actually as clear as you believe. A while ago, some scientists published a very interesting paper called "The weirdest people in the world". They came to the conclusion that findings in psychology are usually based on experiments with only western participants, simply believing that they are sufficiently representative of the whole world. But when some people actually made certain game theory experiments (which are about the most interesting psychological tests there are) all around the world, they were surprised that contrary to what they expected, people in other regions of the world would sometimes behave completely different than what they expected from the results of earlier tests.

http://freethoughtblogs.com/pharyngula/2013/03/01/we-are-the-weird/

http://freethoughtblogs.com/pharyngula/files/2013/03/Weird_People_BBS_final02.pdf

Economic calculation problem. U.S.S.R was cnetraly planned toward military spending creating countless dead-weight losses and dragging the whole economy with it. Very similar to what is happening with the U.S.A today. Only decentralized markets are able to have some semblance of direction toward optimal and efficient goals. 

Although I'm sure the communists will say it was because of capitalists compromising socialists states and if the world were all socialist these states would've never collapsed.