The reason King Lemuel’s mother didn’t want him to drink is that he might “forget the law, and pervert the justice of all the afflicted.”
At the end, the exhortation is:
Open your mouth for the speechless, In the cause of all who are appointed to die.
Open your mouth, judge righteously, And plead the cause of the poor and needy.
When someone is spending time on self-indulgence, which is characterized using “women” and alcohol here, their focus on doing good is diverted.
What a king should do is to help the afflicted, those appointed to die, the poor, and the needy.
Is this also what people in general should do?