I think they are saying only rich people can fully enjoy skyscraper trees (i.e. they can lie on the ground). Pleb can just watch but never touch the trees.
Right, but I think its a bit unfair to compare skyscraper trees to parks. It doesn't have any relation to 'real' wilderness, these are more like balcony gardens with very large potted plants.
It is probably about a mental association of decorative trees in the city-dense areas with public space and the off-limits skyscraper tree space gets in conflict with this association. Don't worry, in time they'll get used to it.