Zero-Coupons do have a peculiar tax obligation. But they also have a face value and a maturity date. Something stocks, and most other classes of asset don’t have.

There is no interest free loan on stock. Capital gains and income derived from trading securities is fully taxed. What you’re arguing for is a wealth tax, a completely seperate category of tax from income tax. But you’re making this argument using highly deceptive language, and what seems to be a rather poor understanding of how the existing tax system works.