Aside from inheritances, it's very rare for someone to get rich without working extremely hard. You see them now, when they're rich. You didn't see them when they were putting in long hours and not taking much home. Worse, you don't want to think about it because it might shake your feelings of righteous moral superiority.
As to the others whose hard work helped the entrepreneur get rich, they were paid for their work. Don't pretend they were exploited. They worked for the pay they got because they valued that pay more than they valued their free time, and because it was better than their next best opportunity. It was a win-win; they won and got their fair share.
Jealousy, not ethics, is the motivation for posts like this.