Mutt, I think the repercussions of such action would be considerable.
No or negligible night operation means that other movements have to be crammed in during the hours when a curfew does not apply. Ever seen LGW/LHR when the night ban ceases in the morning and all the resultant congestion? Not to mention the waste of fuel with aircraft having to hold either in the air or on the ground with APU running etc.
If you are in business you want your shop open as many hours as possible. Whilst night operation may not be popular with aircrew (me included) it means that the aircraft can complete more rotations and/or be positioned strategically for flights later on in the day.
If the mamby pamby social do-gooders succeed in closing the airports at night then what's next? Even more complicated departure/arrival procedures with all the ramifications for flight safety? Just how far do you take this sort of thing?
I have every sympathy for those affected by aircraft noise but if you go and live near an airport please do not complain. Aircraft noise is far less of a problem than it was even a few years ago with modern equipment etc and the noise generated on the roads in many areas is a far bigger issue and little seems to be done about that.