Plus,

1. If you criticize it, "you don't understand it" (you have not "seen the light").

2. People identify with it - it becomes part of their personal identity. ("I _AM_ a Scrum Master.)

3. People parse the words of the Scrum Guide, looking for hidden wisdom. (Hint: it's not there.)

4. One is expected to follow Scrum to the letter (Scrum may not be modified) - just like a religious ceremony - otherwise, it is not "perfect" and you don't get the benefit (or the blessing).