Today no one pays tax on stock until they sell it. What this guy seems to be proposing is that no one except founders pays tax on stock until they sell it. He calls that "distributive justice" but I have a hard time seeing the justice in taxing the same asset differently depending on what hat you happen to be wearing.
I've been waiting for this stupidity to get suggested... more reason to not move your startup and your entrepreneurial self to the U.S, imho.