"You talk about schools as if they were all the same and as if you had experience of every single one of them."
I have limited experience of secondary schools, but extensive experience of primary schools, the culture, the rules, DfE and OFSTED expectations, the responsibilities, targets, budgets, G&T .... you don't need to visit every school to know how the system works.
As I've stated in other threads, there is simply no way any state primary with 25-30 pupils in the class can cater well for the brightest children. They can't even cater "adequately". If they are they are likely failing in their jobs because their focus should be on the children who are struggling, not the bright ones.
I completely agree with you that there should be some motivation from the child, but by the time they reach secondary school, our system has knocked a lot of the interest, enthusiasm and curiousity out of them. Schools work methodically, year after year, to average these kids down (even though teachers don't realise/won't accept this). Schools don't celebrate intelligence and are shy to recognise academic achievements publicly ... in fact, they play this down. They don't even rank performance competitively. Who's top in your DC's class for English? Who's at rank #5? Nobody knows.
"We can't discuss things like that!"
"It's not helpful to rank them! How awful!"
I'm not saying this is right or wrong, but it's a fact that underplaying academic ability has become an art form. That ain't a big motivator for the gifted child. These children need to have challenges, they need to achieve, they need recognition for achievements that were hard earned.
"I heard my also-gifted niece proclaim that "of course the teachers can't expect us to do any work if they don't make it fun for us all the time". "
But is that entirely her fault? How and why did she come to expect, after seven years of primary school, that it has to be fun all the time? Schools dumbing down material to better engage slower learners comes back to bite us in the ass when the other learners reach secondary.