The problem here is that when an "investor" "earns" a rate of return due to capital gains, we ought to recognize that these gains are not due to capital perform

The problem here is that when an "investor" "earns" a rate of return due to capital gains, we ought to recognize that these gains are not due to capital performing useful work (e.g., capital used to found a business) but are the result of speculation. Whether the speculation is long-term or short-term is immaterial. Because of this, aside from the company's IPO, stock market "investment" ought to be discouraged in favor of useful investment. Therefore I see no reason to tax capital gains at a rate lesser than that of income.