From everything I have observed, as a resident of Fairfax County for more than 40+ years, the quality of the teachers in the public schools has been in continual decline.  Strong standards to ensure basic competency in the instruction areas is critical, but the idea of "cultural competency" is a complete distraction and utter nonsense.  These types of initiatives are almost certainly the reason why the instruction in the County public schools is so mediocre.  For the most part, the academic achievements of students in the County schools can be attributed to development of students at home and not to what is occurring in the classrooms where the teachers are truly incompetent.