I haven't RTFT because people made so many valid points on the first page alone.
However, I'll add my twopennorth as a secondary teacher of 14 years who left the profession around 18 months ago. One of the drivers in my decision to leave was behaviour in the classroom (although certainly not the only driver) and one thing I will say, after a long period of reflection, is that the school system itself isn't fit for purpose. We expect young people to understand and accept that they must sit still and listen for long periods each day, whenever we tell them to, despite the fact that this is developmentally inappropriate. We sanction them for questioning authority - even if they do so politely. As a society, we have accepted unquestioningly that keeping children and young people indoors for many hours a day, forcing them to learn what we tell them they must learn, regardless of their interests, aptitudes and ambitions, telling them they must all conform to the same rules and regulations regardless of their personality types etc etc, is an ok thing to do. Their individuality, their right to an input in their education, to choice about what they learn, is suppressed. We do this because, in order for society to function, parents must work and so children must be occupied elsewhere in large groups. As a result, conformity and uniformity is the only viable approach. Schools as we know them now would struggle to contain children without these things. That doesn't make them ok.
Before I get jumped on, I completely agree that respect has been eroded, gentle parenting carried out ineffectually and the institutionalisation of children from being babies in nurseries have caused problems. Socially, there has been a perfect storm of conditions which have led to the behaviour we currently see in schools.
But some of it is also young people rebelling against a system that isn't fit for purpose, a system that doesn't respect them as individuals, so why should they respect it?
For so many reasons, only some of which I've touched on here (let's not forget the erosion of music, arts and drama, the curtailing of activities other than those related to the curriculum in case grades should fall, the pressure placed on children to meet certain arbitrary standards at certain arbitrary times, overworked, stressed and unappreciated adults doing their best to fill too many roles for too many people and leaving in their droves due to stress, and so much more) schools are broken places full of unhappy children and unhappy adults. I don't doubt that there are exceptions to this - school suits some children and some schools appear to be managing well - but I really don't believe that this accounts for the majority of children and young people. A sad state of affairs. The system itself needs radical overhaul but this would take years to achieve and would need people in high places both to understand exactly what is happening in schools and why and to have the courage to act for change.