I've heard it mentioned in the news several times that the statute or contract in which Mueller is
working under, it doesn't preclude him from being fired by Trump. What is the purpose of not including that preclusion in the statute or contract up front? Why should the nation and taxpayers have to go through all of this time and expense and a year from now, (and I'm sure this "investigation" will run at least a year or more at the very least) only for Trump to throw another monkey wrench into the process further down the road and fire Mueller. Sure it will piss a lot of people off and may even ensure his impeachment, but chances are he would have been headed down that path anyway which would be why he would do it in the first place. So if he's headed towards impeachment, why not piss off a lot of people in the process.
Why wouldn't the people who put this all in motion remove this potential obstacle now and remove any possibility of it now, rather than crossing that road later.