What does it mean by this comment: your writing is not critical enough?

Compare the two examples below and say which is a better example of a critique? What are the reasons for your choice?

Example extracts from a critical review:

Example a

There is a strong positive effect on students, both educationally and emotionally, when the instructors try to learn to say students' names without making pronunciation errors (Kiang, 2004).

Example b

Kiang (2004) gives various examples to support his claim that "the positive emotional and educational impact on students is clear" (p.210) when instructors try to pronounce students' names in the correct way. He quotes one student, Nguyet, as saying that he "felt surprised and happy" (p.211) when the tutor said his name clearly. The emotional effect claimed by Kiang is illustrated in quotes such as these, although the educational impact is supported more indirectly through the chapter. Overall, he provides more examples of students being negatively affected by incorrect pronunciation, and it is difficult to find examples within the text of a positive educational impact as such.