Learning despite exceptions

After 8 years of teaching in various settings and school systems what frustrates me to no end is running into people who whilst working with students from special needs or even so called 'mainstream' students cannot accept ambiguity and nuance in their work. People who succumb far too easily to labeling with a sense of certainty that blows me away. I see as problematic the general tendency to simplify things to the point of meaninglessness amongst educators- I see a plethora of experts, articles and discoveries that tend to sound too authoritative and prescriptive in their thinking- with most of their arguments boiling down to some sort of physiological explanation based on the 'latest' brain research and diagnosis of 'disorders' or afflictions of one sort or another.