Because 21 years of being in court with this guy who isn't paying rent is long enough. This has been in the courts since 1993.
http://www.usatoday.com/story/news/nation-now/2014/04/10/rancher-nevada-public-lands/7540911/
And before 1993, in 1986, President Reagan set the fee schedule for grazing on federal land with an executive order. It has been followed since then, and hasn't been raised a single cent per head of cattle.
It has been $1.35 per head per month since 1986. http://www.kcet.org/news/redefine/rewild/commentary/2014-public-land-grazing-fee-the-same-as-2013-and-2012-and-2011.html
“It’s right because it’s legal” doesn’t seem to be getting much traction.