First off, those employees have been paid already, so I'm not sure what the relevance is. If they agreed to work for 100k/year, and forgo the risk of starting a company, why should they get more than the agreed upon price after the company does well? It may be in the companies interest to give them a bonus to keep them around, but that's a separate issue.
Second, the only way you can argue they created more value than the founder of the company is in aggregate. But they also likely made more money than the founder in aggregate. A company tries to pay employees based on the value they bring. If a CEO makes 10,000,000/year, it's probably because the company thinks that CEO is worth it (adds more value than that). So it's silly to point out that the 1000 engineers below him add more value in aggregate. Why, yes.. they also get paid way more than 10,000,000/year in aggregate.
And if the CEO/founder flat out owns the company then all this talk is irrelevant. It's theirs. They can do what they want. If they hired people to build the company for them and the people agreed, good for them. Sounds like a beneficial negotiation for both parties.
Edit: I'm not necessarily arguing for or against the existence of billionaires. That's a tough problem that I don't think I know the answer to. I'm just saying that pointing out that "employees add the real value to the company" is a dumb argument.