Plants/bushes/trees are genetically coded where the below soil portion, the roots, will grow down and to the sides and the above ground portion will grow up and to the sides. Hanging a pot plant upside down will not overcome its genetic coding resulting in it growing down. It will bend and twist until it is again growing up.
Have you ever seen a tree in the woods that has fallen over pulling its rootball partially out of the soil but it did not die and then while laying on the ground the tree continued to grow but it did not grow laterally or down a slope it was lying on but instead sent new growth upwards? There are at least a dozen trees like that in the woods between my home and the lake that were blown down in Hurricane Fran and they all have grown upwards.
Why? It is genetic coding.
Why tomato plants could be grown upside down is because they are a very soft plant, they have soft weak stems and branches. Any new growth will attempt to grow up but soon the weight will be enough to bend it down and it will then hang and overall grow down. That is exhibited in comparing tomato plants that are staked up or grown in cages and ones that are not staked up or grown in cages. The ones that are staked up or grown in cages will have to more or less grow up but those that are allowed to grow freely will, almost like water, seek an even level and hardly stand up on their own once a certain size/weight is reached.