The term NIMBY is thrown around too much. Yes, there are far too many cases where NIMBYism is taken too far. On the other hand, there are legitimate cases.

I lived in a small, fly-in community for a while. I was very close to the airport, and some people had houses within a few hundred meters of the runway. There was noise, but it was managable because there were only a handful of flights per day (none at night) and there were no jets (the airport could handle them, but it was only intended for emergencies). But that is not the type of airport people are talking about here. They are talking about large airports with constant traffic during most hours of the day and night, with the planes typically being larger and much louder. These are the sort of airports that people can expect a significant loss in the quality of life from. I would expect people to be vocal about it.