It was named after Sherlock Holmes, the fictional detective created by British writer Arthur Conan Doyle (1859-1930).
British actor Basil Rathbone's iconic 1930s interpretation of Sherlock Holmes
In the MPC citation, Holmes' ignorance of astronomy is mentioned; he does not care about it because he regards it as irrelevant to his life and work.
Astrologically, Sherlock seems to indicate what its name suggests: "it's elementary" (Henk Middelraad); also, detective work, observation and deduction; possibly, ignorant of a.subject because of it being regarded as irrelevant..