I would argue that the problem is maintenance. Trees need to be pruned, watered, checked for pests, can get into sewer lines, waterways, etc. To sum up, they require work and one thing that governments hate is extra work.
Yet municipalities never seem upset by all the future maintenance required when they allow new subdivisions with roads, sewer, water infrastructure to support in perpetuity.
I would argue that it's not so much that governments dislike extra work but rather that the populace dislikes the additional tax expenditures that accompany it.
