Making money is generally a positive sum endeavour as long as you're not generating unpriced externalities such as carbon pollution, and as such I don't like the idea that rich people stop working after they're rich. As long as they're not creating externalities we want them to continue building and contributing to society. It's a much better alternative to them relaxing on a yacht somewhere, which contributes nothing.
It's also inaccurate to think that making money by building crowds out other people from doing so. The opposite is the case. It's the same mindset behind the "immigrants took our jobs" train of thinking.