A theory has just started circulating (as of 21/07/2013) that Sherlock, the modern adaption is, in some way, a platform to promote discrimination against people on the Autism Spectrum. Autism, in it's umbrella form, is a group of conditions which affect the way people interact in social situations. Though it is straightforward in Asperger's Syndrome, more severe cases such as classic Autism and PDD-NOS often extend into learning and speech issues.
The main area of the theory is Sargent Donovan, who likes to call Sherlock a "Freak" and a "Psychopath." not because he thrives off boredom and solving murders...but because she could actually believe that Holmes is on the Autism Spectrum, according to this theory.
She sees this in Sherlock's intensified interest in one specific subject (Solving murders, as well as enjoying their existance as it occupies him) and little interest in most others, not to mention a lack of desire to socially interact, only with Dr. John Watson, Detective Inspector Lestrade and Mrs. Hudson - his only friends.
That is her real reason for her discrimination towards Holmes, and the negative relationship between Sherlock and Donovan is speculated to be a platform for promotion of hate against people on the Autism Spectrum.