I'd buy the argument made in the article more if they could explain what harm the scammers are avoiding by weeding those of us who can spot a misspelling as ear

I'd buy the argument made in the article more if they could explain what harm the scammers are avoiding by weeding those of us who can spot a misspelling as early as possible. Do they immediately start investing a great deal of time in a possible "mark" right after one reply from them?