Spelling and grammar edits are always useful and should be encouraged, not rejected for not being more substantive. If someone is willing to take the time to make the content here more readable, we shouldn't throw away their effort just because there is more that could have been done to the post.

I do understand the impulse of the reviewer. Because low-rep users get a 2-point bump for accepted edits, there is an issue with silly minor edits being suggested solely for the easy rep. However, if there is a good-faith effort to improve the readability of the post, as in this case, reviewers should accept or improve the edit.