How about that the feds own huge swaths of land in the west that they use for nothing, and want charge ranchers a fee for letting cows eat the damn grass, or prevent them from using the land altogether? You said that federal land is yours -- well, it's also the Bundy's.
Ranchers are getting hammered -- regulations coming down from the EPA, BLM, NPS, et al, on everything from water usage to trail usage to grazing. The government would rather these ranchers just not exist. These are hardworking, honest Americans trying to make a living off the land that their families have lived from for generations, except that in between the past and now, the government has developed an interest in squelching ranching, and people trying to live their lives be damned in the process.
I maintain that occupying the wildlife reserve was misguided. It wasn't going to end well form the beginning. But these guys are trying to get some national exposure and get other citizens to see what they're up against, and they were trying to help another rancher (which is another story in and of itself).
This didn't have to end with blood. They were misguided, but they weren't hurting anyone. If the feds had just ignored them, they probably would have left on their own.
Now the situation has escalated unnecessarily and even more people, both militia and law enforcement, are at risk of being hurt or killed.
Federal lands have increasingly become the domain of the environmental extremist. The common citizen is no longer allowed to recreate or use them to the exclusion of critters and plants. those same lands were historically used to supply timber, minerals and yes - graze livestock - for the good of all americans. the federal gov't no longer looks to the good of all people - only the politically connected greenie.
But in a republic, random individuals cannot appoint themselves unilateral arbiters of assets owned by the republic.
Those lands aren't the Bundys' to dispose of, they have no authority to adjudicate title, and by arrogating it to themselves they are inviting a general state of anarchy.
As far as escalation is concerned, these guys were subject to arrest for what they'd already done, and the feds watchdd them travel around, hold public meetings, etc. They had a lot of opportunities to make their point on national TV. They could not reasonably expect to flout the law indefinitely.