Why? From all I have read about Newton, he would have been the employee from hell. A genius as a mathematician and physicist, yes; but a terrible employee.
He became Warden of the Royal Mint and became rather passionate about his new role - even to the extent of working as an undercover agent and personally leading the prosecution of "coiners" in court.
[NB For a fictionalized, but hugely entertaining, account of the relevant time in history I can recommend Neal Stephenson's wonderful "Baroque Cycle" - Newton is a major character.]
C'mon, who wouldn't want an employee who boils a watch and looks at the egg while contemplating the basic nature and equations that make up the physical sciences? ;)