Writing, in general, is an activity that engineers usually put at the bottom of the priority list but it's when you write that you actually organize your though

Writing, in general, is an activity that engineers usually put at the bottom of the priority list but it's when you write that you actually organize your thoughts and think things through. The process of writing the rejection email, even if you don't actually send it, is likely to make you think about why you're rejecting them, and formalize/ reinforce concepts and ideas to keep in mind at the next interview.