Sometimes your own personal preferences are different from what you think would be best for the city or region. When that occurs, advocate for - tell friends, vote, donate, etc. - the policy that you think is best for the city, even if it's worse for you.
Residential zoning is a ready example because split positions come up all the time. I can't count the number of times I've heard "I agree that the city needs more housing and that the current zoning doesn't make sense, but I like it the way it is."
While nobody's going to fault you for putting yourself first, if you want to help improve the city, put it before yourself.
(Of course, often someone believes that a given policy is best for the city and it's also their personal preference. In those cases, my comment doesn't apply.)