[tropo]

The problem is hinted at here: "equity meant providing all students equal access"

What they are saying is that they refused to keep unqualified students out of the advanced classes. Keeping those students out would have exposed the schools to all sorts of accusations of discrimination, so they didn't do it. Parents insist that low-performing students be in the advanced classes, and the school doesn't say "no", so the class becomes a mess of failure.