There are many legitimate reasons to oppose any particular development. In another comment I mentioned concerns about historical and environmental preservation,

There are many legitimate reasons to oppose any particular development. In another comment I mentioned concerns about historical and environmental preservation, for example. Those are valid concerns, which I often share. However, across many cases they have to be weighed against concerns about equity and sustainability. In a better world each "side" would win some and lose some. The problem is that the way municipal government works systematically favors opposition to any kind of new development even of a positive sort - e.g. mass transit, higher density. It's easier to block than to push forward. Any sufficiently motivated group of NIMBYs can win practically all of these battles, and thus things that need to happen somewhere never do anywhere. Put another way, NIMBYism is not so much prevalent (i.e. a majority hold that view) as dominant (i.e. it prevails nonetheless). They're not the same thing.