But saying a belief is irrational or illogical or without evidence or even stupid is not saying that all people who hold that belief are totally irrational, illogical, or stupid.

That in itself is an insult to them as it assumes that every person is all of a piece. Which they are not. They can be very clever indeed, highly educated, rational about everything else, but still believe something that is irrational, without evidence or even stupid, be it about politics, religion, love, a particular superstition, or that buses always come in threes.