I'm not trying to be a troll, this is a legitimate question.
Why do doctors need this level of protection against Corona? If you have ever seen a pneumonia or tuberculosis patient in a hospital you know they typically don't wear this level of protection. Is this basically them admitting they don't know all that much about the virus yet, and are scared?

Also, that explanation that a 30 something Chinese doctor died duo to being exposed more to the virus. Since when is this how viruses work? Why don't all doctors die, then? I'm not a medicine or biology major, but I'm not entirely ignorant on those areas, and I still don't understand this well. Can someone more knowledgeable please clarify these things.