Anyone who thinks that the American people could stand up to the government is kidding themselves. American forces kill opposing forces at a rate of 1 to 20. Against untrained civilians (American or not, armed or not), the kill ratio would be astronomical.
That ratio was even worse at Lexington, when no more than 100 militia confronted no fewer than 200 British troops. Eight militiamen were killed, only a few minor injuries on the British side (including Major Pitcairn's horse). Well I guess that means the Colonists should have rolled-over right then and there, because resistance was obviously futile against such a vastly superior military force.
The objective is to have a means of armed resistance. That some speculate this resistance may or may not eventually prove effective in the grand scheme of things - no matter how well-considered - is irrelevant. The idea of the poorly-trained and equipped Continental Army having any hope of defeating the world's greatest military power was patently absurd to some in 1776.
Many in the Continental Army questioned whether the British would be defeated in the end, but having to live a long life with one's dignity and self-respect gravely injured by rolling over belly-up just to save one's skin was a worse fate than premature death. I'm sure you would have been among those advising acquiescence because resistance was a risky proposition. One might even get hurt; surely nothing can be worth that!
The overriding goal is
deterrence. Academic discussions speculating to the outcomes of armed civilian resistance against a superior professional military force are great and all, with many documented successes and failures throughout the course of written history to serve as instruction, but the 'big picture' is to substantially 'shift' the cost/benefit relationship to better favor resistance and less favor a government who may develop ambitions of gaining a monopoly on the means of force and using that monopoly to nefarious ends.
Even where it would be reasonable to conclude a particular case of armed civilian resistance was an unmitigated failure, it may actually serve a greater cause. Few would dispute that the Branch Davidians were on the losing-end of their armed confrontation with the government. And so the Davidians lost their battle, but a lot of other things happened as well.
Four BATF officers were killed and at least 16 others wounded. For some, it was the loss of government agents and the clear failure of the initial raid that warranted an inquiry. For others, it was the shocking loss of so many women and children in the fire that warranted an inquiry. Whomever you sympathized with, this armed confrontation placed the government's conduct under serious scrutiny.
Despite significant short-comings in the government's conduct being revealed in the inquiry, such as why the government did not heed the advice of its own experts and the use of a chemical agent on children that is prohibited by the Geneva Convention, in addition to evidence that the BATF was materially less than forth-coming bordering on deception, these concerns were swept under the rug in the "official" investigation clearing the government of any wrong-doing. However, it was all for public consumption, and many remain critical of the government's actions, including people who find the warped beliefs of David Koresh and his activities worthy of disdain.
The government didn't come away so 'clean' in its handling of the Ruby Ridge incident. Again, an armed confrontation that resulted in the deaths of a US Marshal, a 14 year-old boy, and his unarmed mother lead to the government's conduct coming under serious scrutiny.
Randy Weaver and Kevin Harris were acquitted of criminal charges relating to their role in the armed confrontation. The government settled the Weaver family's lawsuit for $3.1 million. A federal judge issued a scathing decision criticizing the government's handling of the matter, implying the entire case against Randy Weaver was a witch hunt bordering on entrapment.
All of this, not because Weaver was a criminal the government believed worthy of putting behind bars, but because it wanted to turn Weaver into a government informant.
The government cannot afford too many of these kinds of incidents, because the more frequent they are, the more difficult it becomes to dismiss them either as 'isolated incidents' that are not evidence of a more sinister problem within the government, or by demonizing the victims, making it easier to ignore the government's abuses because the victims 'deserved what they got'.
These things keep the government honest because being put under the microscope is exactly how patterns of abuses indicating a more sinister problem within the government are discovered. The government may be able to deflect some criticism by hiding behind the unpopular beliefs of the Davidians and Weaver, but not everyone believes it has become OK for the government to kill Americans because their beliefs are unpopular.