I don't really find this a compelling argument at all.
Entrepreneur is not simply a "risk taker." It is a very specific sort of risk taking that we consider entrepreneurial. Specifically it is the risk taking of a person with capital or access to capital.
Construction workers take very real risks every day by showing up to work. They risk bodily injury or death in many cases. But his sort of risk taking isn't called entrepreneurship and the market system certainly isn't offering them outsized rewards for their risk.
I don't think it's possible to have an honest discussion about the merits of a capitalist market system without acknowledging the role of class.
I also reject the idea that the only alternative to a profit-driven market economy is central planning, but that's probably beyond the scope of this conversation...