>Style manuals have their place but are hardly scripture, and there are countless examples of great writers breaking every rule in the book. Indeed, Strunk & White breaks its own rules, sometimes when describing the very rule it's breaking (which is part of its charm [1]). So even if your claim were correct, it wouldn't prove anything.
Breaking a rule ocassionally is not the same as not having the rule on the first place. For one, they can "break their own rule" precisely because the rule exists. They break the rules they set with caution and only when the feel it is needed. That's the way it is with most rules, about writing or anything else. The rule provide a guideline for the 90% of times.
(Edited to be less irritable.) You haven't replied to the main point, which is to give examples of your alleged rule from the three style guides you cited. As far as I can tell, it's not in any of them.
Breaking a rule ocassionally is not the same as not having the rule on the first place. For one, they can "break their own rule" precisely because the rule exists. They break the rules they set with caution and only when the feel it is needed. That's the way it is with most rules, about writing or anything else. The rule provide a guideline for the 90% of times.