why is aviation full of unhelpful idiots
It's not. The problem is the small minority of idiots who give the rest of the good, professional people a bad name. It happens in other industries / services / the NHS, etc too. Just as in the NHS they can make their presence felt at the most inapropriate time with potentially disastrous consequences. The vast majority of pilots both Commercial and Private always act professionally but it's the handful of unprofessional idiots who get noticed.