"or" is mentioned 481 times
"but" 247 times
"not" 212 times
"must" 161 times
"always" 85 times
"must be" 80 times
"but not" 22 times
"Mandatory" 14 times
You draw your own conclusions.
Don't believe my numbers? READ THE BOOK
Not all every usage for the word ‘or’ indicates an alternative- if that is your point- and perceptible since the machine has many options, but some of the usage of the word is to forewarn- ie/ or “else"