It's a matter of where they might be used. Residential and small commercial roortops make sense for these - as well as the units that duct downwards to an enclosed turbine (although those don't swivel to accommodate changing wind direction). There won't be just one solution to converting wind energy into electrical.
Either way, energy conversion is only *part* of the problem. Getting the energy to the grid is also necessary. Rooftops are attractive as there's already connectivity. Ditto ground level around big turbines and around solar farms.