I said hunting AND ranching. A pig farm is a kind of ranch.
And it’s a misconception that deserts are completely bereft of natural resources, plenty of civilizations have thrived in deserts, especially ones that have an enormous river running through it, which the Barrens and Durotar would qualify as.
If Orcs did do agriculture, it would be with by using the floodplains of the Southfury River. We’re not really shown that, but if we’re going to bring real life agricultural practices into this, then that’s something that should be considered too.
But this is all besides the point, we are not shown the Orcs being food insecure (if anything, we’re shown more humans having food insecurity thanks to the drought in Westfall), and they are not clearcutting Ashenvale to make way for farmland, they were gathering lumber to build houses and weapons of war.
Imagine thinking the main race of the franchise still don’t get enough attention ignoring all their leaders are always the center of all plot attention. Delusional.
Ranching of arid environments is also a low yield process. It doesn’t sudden compensate for land type and produce anything close to farming.
It is true that deserts are not totally absent in resources. But they are notorious for being unable to support cities. You either need to irrigate (and farm) or import.
You still need quantity to get quantity. The yield of cactus in a desert is low, so the yield of pork is low.