“To be idle is a short road to death and to be diligent is a way of life; foolish people are idle, wise people are diligent.”

I wouldn't call idle people foolish. Those people are are idle need some guidance and look deep within themselves to become more wise and diligent.

Idle people are foolish because they know they could do better for themselves but don't. They need to help themselves!

It is OK it is your view.

Idle people are foolish because they are ignorant. Foolish people need some guidance to become more wise and diligent, and when they do, that doesn't mean they weren't foolish to start with.

Doesn't it matter too how you define idle? If in meditation or seeking the meaning of life, wouldn't it look idle to another human but in the spiritual realm be diligent?