Only because one of the most respected state schools in our town seems to do just that.
Admittedly my sample size is tiny but the two people I know (work colleagues) with DC's at the school have ended up paying for extra tutoring to get the dc's higher grades. And this was suggested at parents evening by the teachers.
I was a bit surprised that the teachers were so pro-tutoring. Makes their exam results seem a little cheeky.
My DC's are still at primary level so maybe the whole world of tutoring is about to open up to us
.