I think one of the reasons - one of many - they are up in arms is that the whole financial package we currently have which is largely national, will become fragmented, and pay scales will become localised - either geographically or organisationally. Unions and collective bargaining will become increasingly obolete - resulting in dramatic fluctuations in pay for people doing the same job. Another reason is that an academy organisation could change curricula and syllabusi even quicker than the Government is able to do.
I think that there is something much more insidious than this at the heart of this policy.
On the surface, it looks as though the Tories would like their sacred cow "market forces" to be the determinant influence on education and the costs of education and, in consequence, education would become "more efficient".
I suspect that this is bovine faeces.
The real strategy is for central government to become the
sole paymaster for state education and hence its sole controller. Primary and secondary education can then be under total Whitehall direction. And the Tories would be doing their friends in the independent sector a huge favour by driving thousands of fearful parents into spending more than they can afford.