Why does AEAT pension campaign believe members should feel aggrieved?

There are several reasons including the following.

AEA Technology was allowed to enter a pre-pack administration and default on its pension liabilities, despite it being an apparently profitable company and actively recruiting.
The transfer of service at the time of privatisation was said to be secure and the government does not intending to honour this promise.
The AEAT pension scheme was set up to be at least equivalent to the UKAEA one, but the government is not intending to fulfil this statutory requirement.

What does the AEAT pension campaign hope to achieve?

The reinstatement of pension rights as promised by the government at the time of privatisation.
A thorough investigation into the pre-pack insolvency of AEA Technology, including the roles of various interested parties, including the pensions regulator, the PPF and the trustees.