1. Educational system and institutional problems. The employment and promotion of university teachers often pay more attention to academic qualifications and academic achievements, while ignoring teaching ability and teaching quality. Therefore, some university teachers may pay more attention to their own research and academic achievements, but not enough attention to teaching, resulting in poor classroom quality.

2. Lack of teacher training and teaching resources. In some areas, teachers' training and teaching resources are insufficient, which leads to the lack of teaching skills and experience of some university teachers, and can not effectively impart knowledge and stimulate students' interest in learning. In addition, the shortage of teaching resources may also cause some university teachers to be unable to use modern teaching tools and technologies, which will affect their teaching effect.

3. Self-cognition and attitude of university teachers. Some university teachers may think that they have enough knowledge and experience, but they ignore the guidance and inspiration to students. They may be impatient with students' questions and pay insufficient attention to students' opinions and feedback, which leads to the decline of students' learning enthusiasm and grades. In addition, some university teachers may lack enthusiasm and passion and lose enthusiasm and motivation for teaching, which will affect their teaching effect.

4. Changes in the needs and expectations of students and society. With the development of society and economy, the needs and expectations of students and society for university education are constantly changing. Some university teachers may not be able to adapt to this change in time, resulting in their teaching contents and methods not close to the needs of students and society, which affects their teaching effect.

5. The work pressure and workload of university teachers. The work pressure and workload of university teachers may be heavy, and they need to undertake many tasks such as teaching, scientific research and management at the same time. Some university teachers may be unable to fully prepare lessons because of lack of time and energy, which leads to poor classroom quality.

6. Teaching evaluation and incentive mechanism. In some areas, the teaching evaluation and incentive mechanism is not perfect and fair, which may lead to the lack of motivation and enthusiasm of some university teachers, and the lack of seriousness and responsibility for teaching work, thus affecting their teaching effect.

In a word, there may be many reasons why college teachers are so watery in class, which need to be analyzed and solved from the aspects of education system, teacher training, teaching resources, teachers' self-cognition and attitude, students' and social needs, work pressure and workload, teaching evaluation and incentive mechanism.