I think that the most important potential with vertical farming is not the smaller area requirement, but the tremendous water saving that can be achieved.
For example in areas like the Middle-East, agricultural irrigation takes a huge and increasing toll on the water resources [1]. This along with the large rivers of the world (where the irrigation water usually comes from) being constantly more polluted may well increase tensions in these arid regions.
If by vertical farming techniques the need for water can be reduced as dramatically as the article states ("Aeroponic farming uses about seventy per cent less water than hydroponic farming, which grows plants in water; hydroponic farming uses seventy per cent less water than regular farming"), this by itself seems like a worthy effort for certain regions on the planet.