more honored in the breach
Hamlet’s line, and the common misuse.
More honored in the breach than the observance means the custom is better broken than kept. It does not mean “people break this rule a lot.” If you only mean that the rule is often ignored, say that. The phrase is from Hamlet. It is a cliché.
Examples
UseThe custom is better broken than kept.
AvoidThat rule is more honored in the breach. (If you mean only that people ignore it.)