@ProfessorPlum168 this year, for the first time, I opted out of a letter. One of my students had an awful first marking period, but really turned things around after Christmas. I told her I would be happy to write her letter, as I could concentrate on her upward trend. But then she ended up falling back into old habits. On last week’s final (which counts heavily in her grade and could have conceivably pulled her up) she left most of the 10 point questions blank and failed horribly. I went to guidance and said that the only letter I could truthfully write would NOT help her get into a college. Even her attendance was outrageously poor. (And, yes, guidance has been on top of things-- serious issues at home.) So one of the guidance counselors said she would take over.
Beyond that, though, no, I don’t refuse kids. Writing these letters is part of my job.