You are an optimist, or we are discussing different age-groups.
A person should be valued for what is between their ears not between their legs. However, what is between the majority of peoples' ears is a wholly inert substance resembling lukewarm porridge which serves no purpose other than to stop their skulls collapsing! As children and as teenagers, they shoal like fish and their behaviours are, in the main, consistent and predictable.
The first differentiation in behaviour occurs along lines of gender/sex. Why, I do not pretend to know, because varying parental approaches seem to make no difference.. The next, in the teenage years, involves the division into subcultural groups, which varies from a simple difference in the soccer team supported to the vast gulf of mutual contempt and hostility between Goths and Chavs. Very few grow beyond this as adults, sadly.
In the matter of education, comprehensive, mixed-ability co-educational methods are ipso facto "one size fits all". That is the problem, and will remain the problem in default of every child having a personal tutor. By separating the huge, homogenous schools into smaller, more diverse institutions, we could provide conditions more closely suited ot the needs of students.
Young males are without doubt the most naturally toxic section of the community. The recent scandal that emerged here around a culture of sexual harassment and assault in co-ed schools only reinforces the necessity of keeping them away from girls. Our ancestors understood this and created systems of harsh discipline and Spartan conditions in boys' schools with the aim of promoting self-discipline as the only way to avoid punishment. Stoicism was also inculcated to bring about the recognition that being satisfied with what you have is better than obsessively pursuing what you can't get. These methods may have had unintended and unpleasant results in some cases, but generally speaking produced generations of useful and productive young men, as opposed to todays' self-indulgent, self-pitying, whingeing, Trump-voting, criminal-minded layabouts!
