Because the people with political clout are the ones that benefit from the housing shortage.
You could be an owner, in which case the skyrocketing value of your property is something you'd like to defend.
Or you could be a high-income renter, in which case you're willing and able to pay the sums necessary to live in a neighborhood of quaint, charming 3-story buildings, damn the consequences to people around you. This would be the "neighborhood character" argument.
Both demographics have a lot more sway at City Hall than the working poor.
What I find sad are the number of working poor who are fighting for neighborhood "preservation", since said preservation serves nothing except helping the rich live in a theme park of a 1930s emulation, a theme park that explicitly excludes themselves.