I agree that "problematic" is vague. But you have to be a bit dense to not understand what people mean when they say they want to preserve the character of a neighborhood. That means they generally liked it the way it was when they moved in, and they want it to stay largely that way, especially when it comes to zoning changes.

The word problematic differs because it can be applied to any type of thing (not just neighborhoods/zoning) and has no hints as to what it might mean. Everyone understands that people who move somewhere generally want it to stay that type of place. This is why people complain about gentrification, urbanization, and all other types of neighborhood change. They chose to live in that place because that was the kind of place they wanted to live.