Because he used 40 million dollars of taxpayer money!
This was his show. This is about his report. This is about his work on behalf of the American citizens using their money.
Citizens have a right to hear him.
Anything behind closed doors is unacceptable when it comes to the man who ran the investigation and wrote the report.
What the hell is he afraid of? He said he didn't want to sound political. Well the Witch Hunt was just that and he took the job. He did the cabals dirty work using our money.
So put your big boy pants on and answer the questions in public.
Sit your azz down in that chair Mueller, because you look like a coward. It is just disgusting.