Possible Clues:

• Culturally in decline
• After ten years national organisation becomes degenerate
• Debauched
• Fin-de-siècle poster in suitable setting
• Declining to give years to good books
• Morally corrupt
• One might decline to be like this
• Reflecting cultural decline
• Immoral books appearing at the end of the sixties, say
• Self-indulgent? It's proper embracing a daughter