Rich people consumption is not going to rise (inversely) proportionately to decrease in tax rates and even if it did, the burden of proof is on people who say money in the hands of the rich is better spent than in the hands of the government.
It's not about rich person consumption, it's about rich person investment. Poor people are not going to invest in capital, only someone with lots of cash looking to make more cash does that. The proof is easy, compare economies where capital investment is directed by government versus investment by individuals. It's a no brainer, a million individuals looking to make a buck beats a government bureaucracy every time. That's not even a point of debate, it's a no brainer.
If it were not true, then communism would have triumphed. The fact is whenever economic growth is desired, taxes are cut, that's the first thing 'enterprise zones' do.
Government is notoriusly poor at business decisions, they are a bureaucracy that is motivated by politics and critical decisions are made by a few people. Market economies on the other hand have the collective wisdom of millions and by Darwinian trial and error some real gems pop up. It's messy but far better than government where only one idea gets developed.
Poeple like to point out the internet as a government success. The fact is is wasn't made for economic reasons but for military reasons and the government geniuses saw no value in it initially. Only later when some motivated individuals saw potential did it take off.
Micheal Dell moved from Austin to Round Rock for tax reasons, the geniuses in Austin saw no reason to give him the tax breaks being offered to other entities, or they were motivated by political preference. The point is they saw no value in his enterprise.
The 90% tax rates were not the total effective rate in the 60s, and the public education system is very inefficient and fails in critical areas, I would hardly hold it up as successful.