So you think paying someone worth $75k $60k isn't exploitation?
Well, sure it is; the real question is, what's wrong with that?
The very first definition for "exploit" as a verb is "to utilize, especially for profit; turn to practical account." The word has acquired a secondary, derogatory, understanding, but at it's core, it just means to put something to use.
Consider a programmer working as a solo contractor. He has knowledge--programming--that his client needs. Is the client exploiting him? Absolutely: his skill is a resource laying fallow when he's not working, and when the client employs him, it's put to constructive use. Here's the rub--he's exploiting the client, too: the client has money (or accounts receivable, or what-have-you), and the contractor values that money more than he values the time he could spend not working. Who is exploiting whom? The client, profiting from the use of the contractor's skill, or the contractor, withholding that skill from all except those who pay his ransom? The answer is that both are exploiting the resources of the other, in the first definition, and there's absolutely nothing wrong with that. The exchange of resources (and labor is just as much a resource as capital or physical resources) is the basis of all commerce, and fundamentally, the basis of all human advancement.
Furthermore, yes, I expect to make a profit on my exchanges. That doesn't necessarily mean a straight dollar profit. I work for, say, $60,000 per year. I generate much more than that for my employer. However, I also get other things from my employer, starting with not having to establish my own client base, to engage in day-to-day management, and a whole host of other things. My skill may generate $150,000 worth of income to my employer, but there's no way I could realize that working on my own--the other functions of the company enhance my own value to the point that the sum is considerably greater than the whole of its parts. Is the company exploiting my talent? Sure (again, see the first definition). Is the company somehow being underhanded? Not at all--I know the deal, I'm free to walk away from it at any time, and I've decided that it's more profitable to stay here. I've been an employer, too, and you can bet that I didn't pay everything I made to the employees. If I don't get to keep a dollar, why should I even bother doing the work it takes to employ him? If I can walk away with $0 in my pocket by not employing him, or $0 in my pocket by employing him--and doing all of the work associated with that--why in the world would I bother? If I can contribute extra effort and make nothing, or sit on the beach and make nothing...what kind of stupid question is that?
So--I acknowledge that yes, it's exploitation. Show me where 1) that's a bad thing, and 2) preventing employers from taking profit wouldn't result in massive unemployment as employers get out of the business of hiring.