When people say a duty is to be done. However, that is only done by some. The rules do not stay. Each situation to its own way.
In some situations, it is seen as the rule. In other times, it is misconstrued. You are accused of kicking up a fuss. When others had not done their task.
Is it not right that one should clean up one's mess? It would not be fair to push it to the rest. Why do some get away with what others must do? Under the same boss but governed by a different rule?
To give partiality based on seniority. You would just be losing your credibility. Please follow through the rules you set. That way you'll earn much more respect.
This poem speaks of situations at work, where a practice and duty is being enforced, but other times, partiality is given.