There is no certainty about what this land use would be if it wasn't for hunting. If it was returned to farming, the incentives for conservation would undoubtedly decline.
There's also a good argument that hunting has the lightest footprint. While privately owned hunting areas may be empty of people, most professional hunting outfits have small camps, limited staff and few overheads other than equipment and licenses. Any local training is confined to trackers and a camp chef. Apart from the animals they hunt, their footprint on the land is light.
Tourism outfits, on the other hand, build extensive facilities of largely indigenous material, train staff in a variety of skills and maintain areas for photo safaris. With roads and constant vehicle access, however, their footprint is much heavier.
Associated Private Nature Reserves, which border the Kruger National Park and organize hunts of animals that wander into their unfenced lands, generally use this revenue for conservation. Critics, however, have asked why they require hunting revenue for this purpose, given the considerable profits they make from tourism, and query whether hunting simply supplements elitist lifestyles.