Not mistakenly at all: There is a (definitely valid): "Edit is too minor" rejection reason:
This edit is too minor; suggested edits should be substantive improvements addressing multiple issues in the post.
There is a good reason for this. Allowing small edits would clog the edit queue. Moreover, you earn reputation and a badge for suggested edits, we expect people to put some effort into editing.
A spelling mistake is not going to prevent people from answering the question, so it's just a spelling mistake. Unless the editor improved the post significantly, such edits should definitely be rejected as too minor.