Why do people write low-quality business e-mails?

Why do people write low-quality business e-mails?

The general cost for low-quality e-mail is a fact that the sender is not open taking about by the receiver. so the other words what happen the head doesn't open get conveyed out through the finger tips .for the example that is if you receiving email of the someone and your confused by and so you call on their office and you say I am confused by the email what can you to tell you by meet punish and they mail to you is saying something to what I meet was these. And want to tell you are very difficult by your email.