To help students in a chemistry class resolve their individual questions about course content, they are asked to write nonstop for three minutes about their specific difficulty. In three minutes he proposes and rejects one possibility before proposing two others, suggesting that he can generate solutions but needs help evaluating them. That is, we develop a personal construct theory of how the world works, a theory we constantly consult, modify, act upon, and modify again. Further, students often ignore the comments we painstakingly provide. Instead of grading and judging, consider giving advice as a senior to a junior colleague.
Advice is usually shorter than self-justification, more welcome, and more likely to be used.
Respond according to the assignment's purpose. If the aim is to test, then grade. But if the purpose is to encourage observation, comment on how observant the student is. Some writing needs no response at all, especially if the students see that they are getting something of value from the act of writing. Collect and discard assignments that generate their own reward.