How can you miss a point like this. By the same standard you are imposing on Prof. Dinni, then I can demand that you write me a letter of recommendation (without regard to my qualifications, your opinion of my qualifications, your opinion of my skills, ect.). A letter of recommendation is NOT an official form, it is not required, and it is a GIFT that may be freely given, or witheld by anyone, for any reason. Do you give a personal recommendation to everyone, regardless of your opinion of them? If so, your recommendation would soon be totally worthless.