Those TBHs are very popular in the poorer developing countries. There, among other things, the climate is more tropical, and that's a good thing...flowers in abundance and for longer season. The other big factor is due to little or no money the TBH requires little materials, and basically can be constructed w/ junk. A steel drums split in half length-wise will yield 2 TBHs of very large capacity. Various Charity Organization enlist beekeepers to travel to these regions to help get these people jump-started into beekeeping/honey production for an income producing occupation.
Thought you may like to know that TBHs can also be life changer for some.