Yes, exotic, I would find grammar schooling more palatable if there was a way to ensure only those with the best potential got in, not those with the wealthiest or pushiest parents.
But even then, I would only support the notion if the remaining 80 odd % of DCs also were afforded suitable education, like technical schools or sports colleges. MY DB (who failed his 11+ by such a narrow margin, my parents were called into the primary to discuss whether he should go to the grammar anyway...found himself in classes, unstreamed, with DCs who really would have been better off in Special Education (this was 1972). There would also need to be a lot of fluid movement between the schools: I was at the grammar with girls who managed 4 'O' levels- well, they evidently weren't grammar school material, were they? Yet I also went to my professional training college with girls from other SMs whose O level results were not unlike mine, so not all SMs failed their DCs (though it could be argued that such girls should have been at a GS anyway!)
However, a test that can dictate a DC's entire future at 11 cannot be either fair or for the common good, really, can it?
FWIW, I would like my DCs to go to a grammar BUT purely because, being 'selective', they can (and do) effectively kick DCs out who aren't 'getting with the program'. The schools do not have to tolerate yob behaviour (and of course, the mere fact the DCs have been selected on intelligence means that, sooner or later, most if not all recognise the need to shut up and listen!)
Maybe I want my DCs to go to a school that selects for 'good and appropriate classroom behaviour'! Which is why I bought my way into the catchment of a very middle class comprehensive...