Letters can be a lot of things. Sometimes letters are about love, sometimes they're insulting, sometimes they're ambivalent, sometimes they're begging, sometim

Letters can be a lot of things. Sometimes letters are about love, sometimes they're insulting, sometimes they're ambivalent, sometimes they're begging, sometimes they're threatening. So letters can be a lot of things, but they're fundamentally letters, and some letters are open, like this one. The authors here called their letter an open letter because that's what it is. If you think it's just a whining email, that's a you thing, that's your own personal interpretation of the letter. I personally would not call it a whining email. It's a letter with people raising their genuine heartfelt thoughts.