> since charges were introduced

That's one way to look at it I suppose. The other is that these institutions had a tax break for a long time, not having to charge VAT like every other business. So I think quite a few people see it as a little unfair that the schools for rich kids get a tax break: and it is wealthier families that use private schools for the most part. It's not like these schools didn't know this rule change was coming.

I don't live in the UK these days, but one of the problems with the place is how complex the tax system is. All these little carve outs, sudden % cliffs, rebates and what have you. My first job was writing payroll software in the UK. You think that's the norm, then you move somewhere else and realize how much easier it is in many other countries. Then you get calls from people like "don't charge VAT on vegetables like in the UK": people don't understand the cost imposed administrating an ever more complex tax system.