It was a different time and different situation then. Do you really think our economy today could withstand such a high tax rate? Other countries have tried that, with the result that the rich people sold out, packed up, and left for somewhere else. Sweden, Great Britain, France, they all tried this with the same result: they didn't get the anticipated additional revenue but they did get a smaller tax base cuz the top earners/investors, said **** you and they left.
I can't think of the guy's name, but a professor somewhere did a study back in the 80s on the relationship between tax rates and revenue and found that changing the marginal tax rates didn't really move the revenue needle. Fur sure the rich get richer cuz they have more money to invest, no surprise there. Is it not obvious that if you raise taxes on the investor class that you get less investments in the economy? They'll put less money into taxable assets and more into non-taxable assets or they just leave if it gets too onerous.