Exactly. I live in a big city. It's already dense enough that transit congestion is a major problem. One coworker bought a house a couple of years ago, and in the last year told me that his commute essentially doubled.

Further increasing the density of my city (especially if we do it before putting adequate transit in place to prevent congestion from becoming worse) is not something that I want to happen. Why would I vote for it? I'm happy for density to stay at the same level it's at now, or only gradually increase. I haven't heard a convincing argument for why I should be in favor of increasing density at more than a relatively slow rate.

Cities should look after their current residents. If the residents don't want density to increase, then who is to say that's the wrong policy?