The relationship between profit and wages
At the end of the day, currency (such as $) is just a means of purchasing real goods and services in an economy. Roughly, utility corresponds to consumption. Since you assume the capitalist isn't allowed to consume, there is nothing for the capitalist to gain even if they capture all the currency. 

Here is a slightly modified thought experiment.

Suppose there is one employer and one employee in an economy. Both are consumers. There is only one good: tomatoes. In other words, every credit is spent on purchasing tomatoes, and the real GDP of this economy is the number of tomatoes produced. If the employee earns less wages, then the employer has a larger slice of the revenue, and the employer now can purchase more tomatoes.

Now what if the employer tries to pay the employee almost nothing? The employee might just quit: no tomatoes are produced, and everyone is worse off as no one gets tomatoes. Even if the employee doesn't quit, at some point the employee will be less productive because they are starving from not being able to consume tomatoes. In other words, for the employer that wants to consume as many tomatoes as possible, there is a balance between taking as large a share from the existing pie of tomatoes and increasing the pie by allowing the employee to have enough to be productive.