For stocks and bonds, I have no problem with lower rates. They do help spur the economy. But we know artwork (
https://www.moneylaunderingnews.com...anctions-and-launder-money-the-senate-report/) and now bitcoin are being used to launder money. I am not sure why we demand lower taxes on laundered money. That is one reason why some investments need taxed at the normal rate.
The other reason is more simple. Someone can make a million a year off of investment income and have a tax rate far lower than someone making $100,000. Now true, part of that is social security and medicare. But it just doesn't sound particularly fair.