Problem is that applies to almost any given subject.
People do no say
"I am not a chemist" even though I can probably find an exception to
almost any stamtent about chemisty made by someone without a degree.
Try listening to secondary (high) school Chemistry teachers... they
have degrees and still teach complete rubbish most of the time. I can
understand teaching things slightly simplified, but teaching something
which is actually outright wrong in the name of simplicity is just
crazy.