The proposal met opposition as soon as it was revealed. Mainly on two grounds, from two camps.
The first objection came from the radicals. Planting flowers is not, according to them, radical enough. It takes time and effort to sow the seeds that will one day grow up to be the communities of praxis required to change things in the long term. Flowers, while pretty and inspiring in their own right, are simply not enough. Think bigger.
The second objection came from botanists and ecologists. They objected that the proposal went way too far and would require way too much effort to implement. The flower in question requires a very elaborate ecosystem to grow, and building each interdependent part of this ecosystem would necessitate a comprehensive overhaul of the way the city operates. The creation of proper topsoil alone would mandate changing the zoning laws, in no small measure to ensure that the essential measure of microorganisms could succeed on their own terms. It would also require the active participation of most of the citizens, in an effort to collectively change their praxis in such a way that the sensitive ecological balance could be maintained over long periods of time. In short, the flowers were too much. Think smaller.
Overall, the authors were pleased with this response. It indicated that their proposal was, on average, on the level.