Whoever, legally, is in the right. I'm not too sure the answer to that is as clear cut as we'd like it to be.
I can think of many many ways in which Alton could at least try to be better neighbours, including the choosing of where to put major outdoor attractions to keep the noise down at the perimeter. Through their many owners they have always, naturally, been driven by profit rather than social responsibility, and that approach may well come and bite them in the arse.
On the flip side, these two seem to be unreasonable morons. So fingers crossed.