No they're not made to work for free. That dividend check does not belong to them. They take a job, with a paycheck, and that's all there is to the arrangement, and they know that going into it. Those are the terms.
Labor should not get compensated for that which they are not owed and did not agree to.
It's that simple.
If they don't like the terms, they can go create their own wealth elsewhere, like so many millions of people before them have had to.
Your theory is that labor deserves to be paid something they didn't bargain for, and that does not in fact belong to them. You're arguing in favor of violent theft, because that's the only way such a system can ever be implemented, through extreme violence; there is no other way to give labor money that isn't owed to them, and does not belong to them, you have to steal it with guns.
Here's your scenario: so I have $1,000 to my name. You have $50,000. I don't like that you have what I consider to be capital, and I don't think you deserve it. I think that capital should be taken from you, because you're a rich person compared to me. I think you should have to give me most of your money.
It's a spiral to oblivion, because there's always someone richer and better off, and someone claiming that someone else doesn't deserve what they have. It's a system of envy and violence.