Does the subject want to ask, "What is the reason why China Merchants Bank credit card idle fish brush points are useless?" The reason why China Merchants Bank credit card idle fish brush points is useless is that the activity has ended and the conditions for the activity have not been met.

1. activity has ended: preferential activities usually have a certain time limit, which is a limited activity within a certain period of time. Only by participating before a specific date can you enjoy the preferential treatment. After the activity, you can't brush the points again.

2. Not meeting the requirements of the activity: Some preferential activities may need to meet certain conditions to enjoy the discount, such as spending enough money to complete the credit card within a certain period of time. If you meet the requirements of the activity, you can't enjoy preferential treatment.