There are many reasons why a word or words can show up as mis-spelled. It can actually be the spell checker changed the word to what it "thinks" it is suppose to be. It can be someone in a hurry hitting the wrong letter. Or, it can be someone who has a learning disability such as a dyslexic, who are often extremely intelligent but transpose letters. I would rather be out in the wilderness with someone who mis-spelled words but knew how to survive then with someone who is so uptight that they get off on pointing out grammatical errors of people. 
Some people use "shaming" to keep those they feel are inferior quiet and to make themselves feel "important". 
Funny thing, my mother taught both students who had "severe learning disabilities" and students who were called "gifted". She always said her Sped students could survive in a blizzard in the middle of nowhere but her gifted students would die.