I would say that every rule has exceptions. And the degree of exceptions to each rule may vary from rule to rule. But if one were to eliminate all rules that has at least one scenario where it could be considered as an exception, this world would have no rules at all.

If one were to make a list of all scenarios where a one line rule has exceptions, one would have long documents like 'Terms and conditions' instead of easy to comprehend one line rules that would provide reasonable guidance in a majority of situations.

Thats why it is good to apply a bit of wisdom in applying a rule/advice to a scenario and see if that rule applies to that situation or not, irrespective of from whom that advice comes from and not follow them blindly.