I remember when I was young and maxed out my Roth, also converted a lot into it, and a tax accountant warned me that the government could change the rules so the gains are taxed. I thought, "no way, they couldn't do that!"
Now I see they very well could as a response to arguments such as yours.
I can't say I'm a fan of Thiel's business or writings however many of us rely on Roth remaining as-is. It already has limits. Thiel simply made good investments. We shouldn't punish that unless there was something like insider trading occurring. And that should not impact the existence of the Roth.