I hate these generalisations.
Though I have to admit I was very taken aback when we visited secondary schools the other week and got to the one that caters only to the estates (the others have a fairly mixed intake, from professional to estates). We spoke to several teachers about GCSE options. They none of them seemed interested in the academic subjects at all, but would only talk of vocational courses and BTechs. There was no suggestion throughout the evening that a pupil from this school might, say, want to go on and do Alevels with a view to going to university (and looking at their results, very few do). I was tempted to ask "and how would you support a pupil whose ambition is to go on to a Russell Group university", except ds was standing next to me and would have shown me up.
The impression we got is that they have been so disheartened that they no longer think in academic, high-performing terms. Or at least, it doesn't occur to them to tell viewing parents that they do.