The reason public lands in the west are inaccessible is that right of way law has changed in these states over the course of history.
As ownership of parcels were aggregated, landowners of large parcels wanted to limit passage though their growing lands and the laws were changed at their behest. What a great way to grab more land! Simply make it illegal to access property owned by others. Legal owners could not use landlocked parcels and were forced to sell at a cut-rate price. Public lands have been managed differently and are pretty close to the only inaccessible inholdings left (other than recent subdivisions).
Seems like the solution is to restore historical access through legal change. This is really unpopular with large landowners, especially those with many sections of public inholdings. Not going to lie, I'd like access, but I completely respect the position of ranch and farm landowners. Where do we find compromise? Selling our public lands is no compromise.