Nozick made a classic argument about how naive concepts of social justice are incompatible with a system in which everyday economic transactions made by free will can be honored. He used the wealth of Wilt Chamberlain as an example (although his argument was actually concerned with wage ceilings, the same thinking applies to wage floors).
You can insert the words "for example" before "basketball player," or fill in another profession if you need this to be an argument. I wasn't really trying to make one, because the burden of argument isn't on me.
When someone claims that capitalism requires coercion in order to pay high salaries, the burden is on them to explain why so many high salaries exist, sans coercion, under capitalism. Or why wages have generally been higher in capitalist countries.
Another problem with wage floors (coercing higher wages) is that -- to the extent they are effective -- they inevitably create surpluses. For example, requiring every fast food worker to be paid $30 an hour would create a shortage of fast food (by the economic definition). Requiring every programmer to be paid $200,000 would create a shortage of programming.