Perhaps she expects something different? Private schools in the early years often do give much more emphasis to reading and writing skills because some parents get so anxious about them. Children can learn those skills, perhaps at the expense of creativity, imagination, and a whole range of other things. Writing well is important, but not if children only learn to write beautifully formed tosh. Balance is important.
All state schools are not the same. All plumbers are not the same, nor doctors, greengrocers and novelists.
How can she conclude, from visiting one school, that all state schools are the same? Even given the handicap of large classes (and I agree they are too large) many state primaries are doing an excellent job of structuring their teaching of reading and writing so that all the children learn, at their own right time, to read and write well. Why not look at other state primaries before condemning the lot in print?