Desire to improve one's life is natural, regardless of system.

I agree this is true. Probably no society has operated on the principle of a single sentence, but in this kind of conversation there must be some simplification, so:

Under capitalism, the natural human tendency to seek to improve one's life is compatible with the greater good. By producing more of value to others, one becomes better off.

Under the Marxist slogan, the natural human tendency to seek self-improvement promotes antisocial behavior. Regardless of how much you produce of value for society, you will get the same amount—what you need. If you want to improve your life by increasing time spent in leisure or with family, the incentive is to conceal your ability to produce. If you want to improve your life by receiving more, the incentive is to exaggerate your needs.

This article simply argues that both sides agree on the principles that hard work is virtuous and dishonest parasitism is bad, but only one side provides incentives in alignment with those principles.

The issue of distribution, addressing poverty, will never be completely resolved, because no approach is perfect. But it's clear what generates poverty-relieving wealth. In the United States, capitalism runs rampant, and some people get wildly rich, leading to inequality. The fifty states can be ranked by GDP per capita and they range from New York at $90,043 and Massachusetts at $86,942 down to Arkansas at $44,808 and Mississippi at $40,464.

The GDP per capita of the United Kingdom is $40,284. By this imperfect measure, half the countries in Europe are poorer than the poorest American state.