Here is the difference.
The guys in Oregon are away from everyone, in a remote abandoned old ramshackle government facility.
They aren't really hurting anyone, they haven't violated any laws other than the "takeover." No one is at risk, it is mildly entertaining and there is nothing to be gained by attempting to run them out.
In the same way cops just let freeway pursuits go on until the perp runs out of gas or threatens the public, this is just a no reason not to wait them out situation.
Good to see the peaceful and peace-loving libtards showing their true colors bu demanding another Waco.