1. Why teachers: Because academies don't have to uphold the state agreement on pay and conditions. And quite a few more things besides.
2. Why parents: Because the quality of teachers will decline as good teachers leave. Because the people in charge of education will no longer have a background and training in education.
3. Why childen: because they will put the needs of industry above the needs of the individual student. Because you will have to cram for subjects that will get the institution results that make it look good, and noone will care about your needs and your abilities .
4. Why the local community: Because the local school buildings will leave public ownership, and no longer be a resource that you can legitimately access.
5. Why the lexicologists: Because the word academic will no longer mean something above average?
6. Why the governors: Because one day in the future, someone will ask you what did to protect educational standards.
7. Why the politicians: Because schools not publicly accountable and run by people not educationally trained will be sub-standard, and quite quickly.