Politically, this setup seems to help keep those high-earners voting for lower taxes, which makes sense to them since they're the ones paying the highest overall rate.
And many of the tax “loopholes” involved real estate investment which would be accessible at that income level.
This is such a compelling narrative for the "taxes should be lower" crowd that I'm skeptical. Granted, this is my personal bias. But I would love to see the actual clear examples of how people are deducting like 50% of their income or whatever they'd need to bring their 70% marginal rate down to 35%.