Segregating children according to their parents' superstitions is a great way to create a volatile, violent town where ethnic groups glare at each other across a chasm of mutual incomprehension.
Of course, there's another factor in Hari's case- the same one that motivates Excitable Andy Sullivan:
Most religious schools preach one chunk of reactionary morality or another, all causing terrible harm to children.
[I have written] in favour of understanding and embracing despised minorities like gypsies and paedophiles...
Needless to say, just as Hari's opposition to religion in schools turns out to mean that he thinks schools should be brainwashing the kids into culturally Marxist rubbish, so all this just means he wants to impose his own warped morality:
Some of the new evangelical city academies - models for the new faith schools - openly admit they are "anti-gay" and urge gay pupils to "choose another path". There is a real risk that, having abolished Section 28 by the front door, the spread of homophobic faith schools reintroduces it by the back door for thousands of schoolchildren.
The substantive point though is this: Liberals have been enraged by faith schools for years, yet parents keep sending their kids to them, morality and all. Ditto, these schools keep beating their opposite numbers on the Left so hollow that the L3 are forced to resort to whiny special pleading about faith schools using up all the education so kids at Karl Marx Comp end up studying the history of the letterbox and Jackie Collins' novels. So, the public like faith schools and they work, but Hari and his fellow travellors want to destroy them. Hundreds of years of history and culture will be destroyed in an educational Year Zero, with the kids herded into Nu Schools, whence they will be indoctrinated in a foul and depraved ideology responsible for the deaths of over 100 million in the last century alone. And this guy complains about other people trying to impose their morality ?
Tip'o'the'hat to Laban.
It appears I've had a religious experience - possession by the Demon of Bad Writing. Just to clairfy - I think Hari would be making a defensible point if he wanted schools to follow the old rules for the Officer's Mess ('no religion, no politics') but it's quite obvious that what he wants to impose (not merely offer the choice of) is a school curriculum pushing a very definite religious doctrine (atheism) as part of a very definite worldview (Marxism).