Those seeking to enforce orthodoxy will be in a race to the bottom in terms of freedom of ideas.

Enforcers of orthodoxy can’t allow a borderline idea to exist, because that gives other enforcers an opportunity to one-up them in the moral purity department, and perhaps even to turn enforcer upon them. So instead of getting the margin for error we need, we get the opposite: a race to the bottom in which any idea that seems at all bannable ends up being banned.