My DS1 is just coming to the end of 2 years of a split Y3/4 class. He was absolutely fine about it, perfectly happy, we went along with it (though not all parents did by any means!), decided the school knew what they were doing/ our child isn't the centre of the universe etc etc. Sensible well balanced parent, you cry! However, I believe DS learned practically nothing in Y4. Really. Suited him fine having the (NQ) teacher HAVING to pour her energy into the young, new (and majority) Y3s whilst most of the Y4 swanned along!
Were the DCs all carefully selected according to gender and ability mix? Depends whether 'alphabetical' counts!
Anyway, we have been assured that Y5 will be 'catch-up central' and at least if there were to be a 'duff' year for DS1 it was Y4, not hopefully 6!
You might say 'Ah, bad school, didn't do it right etc etc' because it patently didn't work for most of the DCs, esp the Y4s. However, THEY felt they'd started with a Clean Slate where everyone had a 'fair go'.
However, the Infants had to do a Y1/2 mix (plus a Y2) which went quite well for us with our Y2 boys. Not sure the Y1 girls, selected on age, ability and maturity would agree, though!
When it comes down to it I feel your sneery 'Haven't these parents got anything better to do?' comments can only come from parents who haven't yet encountered the potentially socially devastating effect a pulled apart friendship can have on a shy sensitive soul or the educational disadvantage that can result when the anticipated 'gelling' of a class fails to happen. Or a mathematical, geeky DC is placed in a class with a teacher whom you already KNOW to be hot on art and say dismissive of the 'harder' stuff- you just KNOW it ain't gonna work, sometimes. And may damage your DCs confidence into the bargain. Bearing in mind we're possibly talking 6 and 7 year olds, here.
In an ideal world yes, all DCs would be carefully graded into perfect classes. We also recognise that all will not always go our DCs way but feeling unhappy or worried about the class decisions that are made doesn't necessarily label a parent as 'having nothing better to do'. They may have some genuine concerns. And as for 'teacher knows best', they will do their utmost to try and be fair as far as they are able but we all here on MN endlessly trumpet about how we know how G&T our DCs are- yet unrecognised by the dumb teacher- yet feel other parents are being TOTALLY unreasonable when their knowledge of their own DC is at variance with the teacher's, a view that may seriously colour next year's class selections and your DC's enjoyment of school!