The series four finale of Sherlock cleverly illustrates the dangers of allowing the inmates to run the asylum. The show regularly covers behaviors that would alarm any employer, such as Sherlock abusing drugs, firing guns indoors whenever frustrated, and generally being delightfully bizarre. These oddities are some of the many reasons that Sherlock is a consultant for, rather than an employee of, the local authorities.
They also explain why Sherlock has no regular employees to speak of, unless you count his secret network of informants. This series introduces Sherlock’s sister, who is comprised of equal parts evil and intellect. When she takes over the high-security facility where she has been housed for decades for being “too clever,” all bets are off.