It's not absolute. It's just unlikely in the extreme due to the nature of this government and the people it serves. Do you imagine the members of the military turning on the average people of this country willingly? Unwillingly?
When does caution tip the scales into paranoia? And where is the wisdom in channeling resources (time, money, etc.) into preparation for very unlikely events?
Do you have an asteroid bunker these days? Do you advise people to invest in those places that want to build and supply them for people?
This is a good point. When some say 'we'll fight the govt if they come to take (some or all of) our guns!', the typical response is 'yeah those (insert your favorite derogatory term here) people can't stand up to the US military'. Neither of these statements are helpful, or even accurate given current conditions.
First, the govt isn't coming to take your guns. There may be more regulations, but that won't trigger a revolution. People have to be pushed quite far before they will risk all in such a manner. And we have multiple outlets to address their grievances, elections, amendments to the constitution, even federalism helps in this regard.
To address the second comment, we have to suppose that the people have been pushed far enough that the situation could even occur. It's not the case now, nor in the foreseeable future. But if it were, at some future point, why would the members of the military not be affected? They are citizens, likely with diverse opinions on the subject at hand. More likely there would be some on both sides.
What frustrates me about this situation is that congress is just unable to act at all so far, even though some things, like strengthening background checks, should be easy to get through.