Socialist: "Capitalism is full of exploitation. Capitalist employers exploit their employees by underpaying them."
Randian Capitalist: "Well, maybe the mixed economies we currently have see that kind of thing happening. The problem is that the presence of socialism in our mixed economies socializes individuals to believe that individuals have no inherent worth and so it's okay to sacrifice or exploit them for any bigger end. What we need is real capitalism. Once we have real capitalism, people will grow up with a new ethos. Under real capitalism, a Randian ethos will emerge in which everyone insists on paying others exactly what they deserve, not a penny less or more. Therefore, real capitalism eliminates all exploitation.”
This sounds pretty dumb, right? But socialists often say the same thing in reverse. They claim that socialist societies will create a new ethos in which people will refuse to mistreat one another, will work for the public good, and will abide by various demanding moral rules. They claim that existing selfishness--including selfishness and malice in socialist communes or countries--is the result of past socialization from capitalism.
Of course, it's possible they are right! While most people just assert this stuff because it flatters their ideology, we can at least study how different systems affect things like interpersonal trust, altruism, cooperativeness, trustworthiness, and so on. Unfortunately for socialists, though, the empirics are rather clear that capitalism increases these good things while socialism and traditional society tend to demote them. You can read Markets without Limits for a review of that literature.
Socialists oddly don't seem to take exploitation very seriously despite talking about it all the time. Consider another dialogue:
Socialist: "Exploitation occurs when someone uses their market power--which results from power differentials--to give someone a bad deal that takes advantage of the other's misfortune or differential power."
Capitalist: "That sounds bad. We should stop that if we can. So, I'm guessing then that you think it's really important to foster a competitive market--competitive in the technical economic sense--so that everyone everywhere is a price taker and no one has market power. You'd probably hate it if there were monopolies or monopsonies."
Socialist: "Well, no, what I propose we do is create a monopsony for labor and a monopoly seller of goods."
Capitalist: "Huh? What? I think I must have misheard you, because you just said literally the wrongest thing anyone could propose as a solution to this problem."
Socialist: "No, we'll create a monopoly and monopsony but make sure everyone is super duper nice."
Capitalist: "What the fuck?"
Socialist: "For real."