No, this is the problem with
media representations of preppers. It's a massive overgeneralization to say that preppers "seem to be far more obsessed with guns than with clean water, sanitation, and heating."
With that said, the reality is that clean water, sanitation, and heating are pretty darn boring. It's like prepping 101 to have some available water, a shovel, and a barbecue or a fireplace or a basement to keep warm. If preppers do seem to you (apart from media misrepresentation) to focus more on guns, it's likely because they're long past having basics like food and water taken care of, and guns are more varied than any of the other basic needs.
Every place is different, and maybe guns are less important in your country, but they're very important during collapses in America, whether we want the world to be that way or not. Look back on the social breakdowns in America over the past--the LA riots come to mind--and look at how locals used guns to defend their stores and homes from looting. And those looters were just rioting; they weren't hungry or fighting for survival.