No, it wasn't. A wonderful brush and flower is an idiom describing the use of vivid language to describe a rich image and scene that will leave a deep impression on people. This sentence means that this person's writing is vivid and flexible, and he can express a lot of meaning with very few words. Therefore, it can be said to be a bad sentence, but the degree of derogation is relatively low. It is usually used to describe a literary or artistic work that is very outstanding.