Most, but not all. The Randians come to mind. Even the Buddha encouraged people to be critical, but doesn't seem to have stopped the cults. I was floored to learn a few weeks ago that Buddhism has formalized even when you stop doubting! When you stop doubting, you become a Sotāpanna; a Sotāpanna is marked by abandoning '3 fetters', the second fetter according to Wikipedia being

Skeptical Doubt - Doubt about the Buddha and his teaching is eradicated because the Sotāpanna personally experiences the true nature of reality through insight, and this insight confirms the accuracy of the Buddha’s teaching.

As well, as unquestioningness becomes a well known trait of cults, cults tend to try to hide it. Scientology hides the craziest dogmas until you're well and hooked, for example.