Maybe you can help me understand more then. I don't see how cows could flourish in those areas. For example the calico mountains, or the lava beds in Nevada. I haven't been there but it doesn't seem to me like things would really do well enough to turn around any profit there. Or areas I've experienced first hand, such as palm desert in California. My understanding is that we are removing horses because the land can't support them, so how would it support cattle? Can you break it down for me?
I understand that the government may ask a rancher to do certain improvements and then need to pay them to do it. Is it typical that a rancher would be reimbursed from the government for what they choose to do with their own land without the government requesting it?
Some places require more than 100 acres per cow/calf pair to support them. I have a friend in AZ whose private place is rated at 250 acres per AU (cow/calf pair will require one animal unit). Those areas sure look crummy.
When people lease ground from the gov they get a cheap price. You've probably heard that. But they have to keep records on forage variety and amount, correct any erosion that be is identified ( even if it was just caused by rain), often move or change fence types if a biologist thinks it would be better for antelope migration.
And they CAN'T do anything to improve forage, or fix erosion without the gov's permission. And that can take a long time.
As far as being profitable to run cows on junk pasture, sometimes it's still worth it to a rancher to put cows on a huge area for even a few weeks.
I went to private leases some years ago. I pay more, but I don't do fences or dirt work. And the owners are right on top of weed control, etc. I help, but I'm not financing the whole thing, only to have people chase my cattle on four-wheelers or be told to pull the cows early, without a refund.
There are places where horses can't thrive without a lot of human support. I know BLM gets sued everytime they make a change, but they sure try to please everybody.