Exchanging ideas is essential to a free society. However, when on the tax system a letter writer who is a math teacher says the government ought not to penalize taxpayers who are wealthy owes to free speech the entire equation. The tax system does not nor should it consider a simplistic proportion as the writer advocates, for it is just another flat tax scam that sees no unfairness to one percentage fits all. Progressive tax is based on taxable income meaning income after one has had the ability and means to take care of himself reasonably well.
It is this differentiation between minimum essentials and play money left over that drives the concept of progressive tax. High income brackets are being taxed theoretically on nonessential income—income beyond basic creature comfort— but this is not as severe as it reads. In an enlightened society, even during the 90+% FDR era, loopholes were abundant for such things as capital gains, second homes, mortgage interest and real estate taxes, but primarily for business large and small to reinvest in their activity to maintain and create jobs, thus growing the economy.
As for charities the writer is worried about, FDR implied if you don’t extend the benefactor hand, the government will. That is why since then there have been so many partnerships of government and foundations that have substantially made life better for those in need.