There has never been an actual communist country. Some countries have claimed to be communist, but are in actuality not, a great example of this would be China. So whenever I come across arguments over capitalism vs communism, it seems pretty pointless. Communism sounds great on paper but does not hold up in the real world.
Capitalism on the other hand, while it does work, isn't really that good of a system. Sure 'some of us' can retire before we're 30 and 'most of us' don't retire till we're 65 and that number is getting higher and higher as time goes by. And well wanting to see a doctor and being able to afford to see a doctor are different things. TamaSaga sounds like he's living the good life.
The one good point that TamaSaga does make is that people in America are free to complain about unequal incomes without being dragged from the streets. But that's not really a capitalist thing, that's an American thing, right to free speech. If you've paid attention to history, several times when workers gathered together to protest income inequality and demand for better pay or safer working conditions. The factory owners usually hire thugs or bribe the police to break them up and sometimes people end up dead. Just google 'anti-union violence'.
My thoughts on the manga: It's good for a laugh, I don't think about it much beyond that.