Is backbiting a group of people permissible by saying, "The teachers are hot-tempered" or similar phrases?

It is not permissible to backbite a specific group of female teachers by describing them as nervous, because backbiting is mentioning a Muslim with what they dislike, and it is one of the major sins. However, describing female teachers as nervous without specifying individuals does not fall under backbiting. Yet, this generalization is not free from falsehood, and it is better for a Muslim to guard their tongue except in what benefits them.