What about countries like Germany, Norway, Sweden, Denmark, Finland, Canada etc.? They all have socialist economical systems to some degree, and are not only doing perfectly well without any starvation or labor camps, but are generally considered some of the most successful countries in the world.

Like others have said, communism/socialism is not a political system, neither is capitalism: they're economical systems, and how well they do depends in large part on the government behind them. Socialism is not inherently bad, nor is it inherently good, but the fact is that most countries that have attempted communism have done so through revolutions and ended up as totalitarian dictatorships, which tend to be extremely detrimental to the general population no matter what economical system is used.