How can you argue pt.1 when the kids of high income parents already receive, at great expense but to great personal benefit, the kind of academically segregated education you are arguing against? How is a smart kid from Detroit or Camden supposed to catch up to his intellectual peer who is learning calculus while he/she is stuck in a school right out of Stand and Deliver? Without help one of them is going to Harvard and the other Community College, maybe, and quite frankly that is a waste of potential.
Sometimes the problem with education isn't the building, or the teachers, or the administration: it's the students (and by extension their parents) and if we can't fix them at least we can teach everyone according to their ability.
I can relate to the situations you describe, but they're not going to happen. The link we're all discussing is not talking about making these schools public, free or even accessible. It talks about, more generally, whether segregation should exist.
As for Detroit. Most of Michigan's "gifted" schools are private and NOT free [1] [2].
So you advocate mandatory public education? In fact mandatory boarding public education? -- I can think of no other way to avoid intellectual segregation as surely their are more 'gifted' children in Berkeley than Compton.
So much for the land of the free...
To the point: you are arguing that segregating students by capability increases income inequality - which is false to disingenuous over generations.
Sometimes the problem with education isn't the building, or the teachers, or the administration: it's the students (and by extension their parents) and if we can't fix them at least we can teach everyone according to their ability.