With high marginal rates, the tax shelters the Hollywood rich invested in were less productive investments. Yes high marginal rates will lead to more CPA hours to get around the high taxes, but that is just an example of the Broken Window fallacy. When there is no way around them, very high rates will lead to dead weight losses to the economy as economic activity won't be done.
Because allowing for one idea would lead into another.
70% tax is a start. Not the end. The idea is to find where the "excess" income is taking place and add additional taxes in that area to direct the income into investment and services.
70% may be a start at ordinary income. But does it apply to investments? And then what's next?
I think the key question for Dell and others is: can you show proof that the current approach of lower taxes boost the average individual income of workers? Because right now we're seeing great numbers from Wall Street, but wages are still virtually flat year over year. How does the Dow continue to climb but workers' pay stay the same?
this whole green new deal proposal is "lets go spend billions more dollars on XYZ" a lot of the mental pushback is what are you going to stop spending on today to pay for it? the answer: "nothing, we're just going to raise taxes"
i believe opposition to this is less about can the 1% afford the taxes or not, and more for principled spending