As others have mentioned, one of the problems is that none of the new initiatives that have been made (not just Gove) are given a chance to bed in properly and for the kinks to be ironed out before they're scrapped. Each new initiative or curriculum change means rewriting schemes of work to include the new focus and to train the teachers in how to achieve this, monitor how it is going, reflect and revise their practice etc.
I am glad that my school is now using all the international exams and syllabi. It means that we are mostly immune to meddling and can develop our best practice and drive standards up. I am rewriting the KS3 schemes of work at the moment. There are 5 units per year, so 15 schemes in total. Each scheme takes about 6 hours to write and 16 hours to prepare the resources. Imagine doing this every couple of years! It is rather soul-destroying and not good for the children as my time would be better spent on more detailed marking, intervention sessions and further differentiation.
What is really needed is more teachers, more classrooms and smaller class sizes. As well as students learning better during the actual lesson, the teacher has more time to mark work in more detail and create more personalised learning. In one class I have 34 pupils for a 50min lesson. This gives me about 1 min per student during the lesson to check their learning, help if they're struggling or to extend my highest thinkers. Frequently some students don't get that 1 min because of others needing 5 mins. In a class of 18 that I have, I am able to get round every student every lesson. They benefit. I'm lucky that as a core subject SMT allow us to be slightly over-staffed so we can have smaller KS4 groups, but would make a massive difference to KS3 classes too.
Also agree that it is wrong to bring in changes that affect the current exam cohort. Students become anxious and risk not doing as well, teachers get confused about what has been changed and have very little time in which to change the year 11 curriculum and parents get angry at the schools as they think we are being incompetent or disorganised, as we have to say "no, this doesn't count now. I know we told you that it did, but now it doesn't".
Not all changes are bad, but Gove is disadvantaging pupils for his own interest. The cynic in me says that he wants this current cohort to do badly, so 2015 results are better and he can claim the credit (as others have done before him).