A lot? I know Warren Buffett has similar views, and I've seen other very wealthy liberals claim taxes and climate change were big concerns. When people get very wealthy, they seem to think less about their finances and more about their legacy and public perception, and honestly when you're that wealthy, you have so much that taxes don't really matter anymore.
There are a lot of very wealthy philanthropists, and I think that's because people seek meaning in their life once they no longer get benefit from earning more.