People seem to forget that opening times are also governed by the impact on the local community. Stayed in various B&B's in and outside of Alton, it is surprising particularly if the wind is blowing the right way, just how loud the park can be when in operation. Having a 5pm close means that noise continues until 6pm, 8pm becomes 9pm etc. Then there is the impact of the traffic late at night passing through the village. Then there are the staff, many of whom would have started early morning.
Dont get me wrong, I want later opening in the summer evenings, but, I dont believe everything is down to Merlin , there are other factors at play here....