You say all of this as if I'm some kind of discriminatory, snobbish person: which is quite far from the truth, I can guarantee.
Whether or not you are a discriminatory person is irrelevant to how you act. Your original posts did come off as sounding like there are no bright people going to state schools.
I love the way how you seem to think of the middle class as the root of all evil, as well.
Please quote when anybody said that the middle class is responsible for anything bad.
I believe that a dual-tiered education system would work - provided that selection for grammar schools was handled fairly
Except that we must account that, most likely, it would not be handled fairly.
The brightest students get pushed more in a group of those of similarly high ability, thus driving them on to attain more than they would in a mixed ability group. The other students - those who don't attain as highly - get educated among their peer group at the comprehensive schools, where teachers are no longer stretched to cater for different ability groups, and the students get a better education because of that.
The problem is that even bright students from poor backgrounds get to be looked over because of various reasons. Low class students, despite their intelligence, tend to do worse on tests and put less into school than middle class students because they're conditioned to believe, essentially, that they cannot get out of their situation and that school is a prelude to work. I don't know what the quality of comprehensive schools is, but state-funded schools in low-income areas tend to be poorer and have a lower quality of education, so even the bright working class kids would not have the same advantage (some might say
privilege) that a middle class kid would have. I'm speaking from my knowledge of low-income schools in the U.S., so I don't know how much of this applies to low-income areas in the U.K., but I'm guessing it's a fair amount, so.
If you want an example of how testing results in the situation being stacked against non-middle/upper class children, I offer the example of testing for gifted classes in the U.S. It used to be done based on teacher recommendations, but now that it is done through testing the amount of poor black and Hispanic children entering the gifted program in NYC has dropped by 27%, even though 66% of the city's kindergarteners are black or Hispanic.
Like I said, I don't know much about how grammar schools work or how admittance is based.
And of course, as you said, middle class parents
will continue to tutor their children so that they can get in. Parents tutor their children for everything (even for gifted tests, which is the equivalent of studying for an IQ test). Of course, tutoring requires paying money for tests and tutors, which I'm guessing most poor families can't afford, so... yeah, it's not very fair.
And that is the route from a poor background out into a well-paid, top level job
Except for that people from poor backgrounds don't have the same advantages that middle class kids do. The playing field is not level so that smart poor children will have more difficulty competing with smart middle class children through no fault of their own.