I think that a part of the problem is strictly related to the difficulty of writing English: our children have no problems - or have LESS problems- since words are written in the same way in which they pronounce them, and they don't need to imagine or remember the correct spelling.
Anyway, there is another aspect of the problem which seems to be common : it seems that students cannot obtain from the schools a good instruction - or at least skills enough - as before ... years ago...
But we cannot forget that we are making a comparison between very different situations: now we are trying to let everyone have an instruction, then just few -usually rich and/or clever - could.
For example, I am now teaching at the University, while my grand-mother was not even able to read and to write - well, not exactly: she was barely able to write his name - and I have this sweet memory : we were together making exercises - she (75) was slowly writing her name, while I (5) was learning to write my first words..

Emanuela