That's not true. Families build wealth together. My children don't do my work, but they work with mom to keep the house in order while I do. It's a family effort. Without the support of my wife and children, I would not be able to produce nearly as much as I do (note: I'm not wealthy, I just happen to value the money I make).
If your children provide you support, great! You have that advantage vs. people that don't have children or that have children that are, let's say, a drain on their time.
Your children still did not earn income, you did. And you got a tax break for that as well in the form of dependents. You are asking to double-dip here, which is unfair.
If you think that's double dipping, then you have a sad view of the world. Here's some news - when you actually earn a decent income, child tax credits do very little to offset taxable income, especially when you are a business owner.
If you decided to give it to your children or whatever, it'll get taxed just like if you tried to give them that much money before you died. If in your will you decide to give it to a non-profit charity instead, it's not taxed.
You aren't taxed for dying. The person who died isn't taxed at all. It's the people that are still alive that are now receiving money that are taxed.
How is any of this unfair? Your children didn't do anything to earn that money. Why should they get it at all?