"Children need to be made aware at as early a stage as possible that their needs and requirements are not always (in fact rarely are) paramount."
But surely they are paramount? The whole point of an education system is to give children the skills they need to develop, to pursue a career, and (not least) to pursue happiness. That's loony-liberal charity, that's one of the foundations of our society. But if that's not putting the consideration of children first, then I don't know what is.
Further, I don't see how the school-pride doctrine is essential to those aims at all considering that as we demonstrated earlier it is proud of the fact that it proudly excludes people and ostracizes the different. In fact I think it's actively detrimental to them.
"
As surely as his haircut will have little or no effect on his education, similarly if he had a “conventional” haircut (as decreed by the headmaster) then that would have no influence over his education either"
I doubt it effects his brain chemistry or anything like that, but the cut clearly means a lot to him. And these things are only 'different' or controversial if you treat them as such - go into any sixth form with no strict uniform policy and spend a week there, and it becomes pretty pedestrian.
"School is not the place to “challenge authority”"
Then where is? I'm guessing you probably don't think the home is appropriate either, and considering that we're supposed to learn in school, then it strikes me as an ideal place to ask questions and investigate boundaries. Challenging authority is a basic entitlement - if somebody won't or can't explain to you why you ought to trust their authority, then you probably shouldn't. That's not anarchism or radicalism - that's just making sure that authority is the best that it can be.
Now, I admit that this doesn't have a huge presence in the workplace (but it's not entirely absent either, depending on rank/exact occupation), but it strikes me as a valuable and worthwhile thing for wider society at large.