[tjoff]

If that weren't the case, why would you feel apprehensive, uncomfortable, or awkward?

Because it is irrational? People can have phobias against pretty much anything, even if you know that the fear is irrational and groundless you can still be petrified by it.

Shyness is particularly common among small children, I don't think they fear negative judgment.

[drumdance]

Yes, it's irrational, but usually if you ask someone to really unpack why they fear X, they can explain an exact scenario. Often just the process of explaining it oneself helps you get over the fear.

Children certainly fear negative judgement. Think how many times they hear the word "no" and get a nasty look from their parents.