Because I was simply coming up with a counter argument not advocating for a position.
I could support the fist line by saying investments are taxed at below average rates including loans (bonds) which are not double taxed. And a flat tax without any form of tax breaks is the only fair solution.
But, again not trying to support a position just disappointed with the way taxes are discussed. Arguably all people deserve a tax break, but the only way to do that is reduce spending.
Indeed, the "root argument" in favor of taxation is fundamentally all about "having other people pay more so that I pay less". That being the case, why did you start out by saying that "investments should have much higher tax rates", only to contradict yourself later?