I don't get the issue that people have with preppers.
Sure, some of them have a relationship with reality that can be described as "casual", but that's not sufficient to discredit the concept altogether. It is wise to consider the basic claim behind the argument for preparing, which I shall do below.
Disasters happen. These disasters routinely sever the infrastructure that delivers fresh water, electricity, natural gas and other utilities embedded into that thing we call "The Grid". When one or more of these utilities goes down, we expect to be able to contact the provider(s), report the outage and get an estimate on when that outage will be restored. When this happens as part of a disaster, even if we can do that we have no expectation that service restoration will occur in the less-than-a-week timeframe that our current physical economy is built around. Food that requires refrigeration soon thaws and either must be consumed or must be discarded. Basic hygiene practices--showering/bathing, etc.--get cut back to conserve on available potable water, and climate controls are eliminated when air conditioning and heating technologies (that require electricity) shut down. This disrupts the everyday pace of life that most of us are long accustomed to in the world. There's nothing good about such episodes, episodes that--I repeat--are predictable and therefore can be prepared for.
While hurricanes/typhoons/earthquakes/tsumanis are certainly part of this matter, what I'm thinking about are far more frequent: floods, thunderstorms, blizzards, droughts, tornadoes, unseasonable deep freezes, and similar weather patterns. Where I live my primary concerns are storms and blizzards; your location will have other known patterns that can inflict disasters to account for. Therefore I suggest that you tailor your preparations for the specific environment wherein you dwell. These things happen, they can and do reach severe levels, and they can reach such extremes that the Grid can be knocked out for weeks or months at a time. Even more moderate outages, if they persist long enough, can become very dangerous.
Yes, most governments will come forth to intervene, but--regardless of that agency's benevolence or malevolence--they must secure themselves first and foremost; an agency cannot fulfill the mandate expected of them until they are certain that they can reliably act in that capacity, so they always take care of themselves and their own first. In and of itself, this is not some horrific conspiracy meant to do wrong to the population; it is nothing more than a necessary precondition for getting anything useful done in a timely manner. Even under the best circumstances, responding agencies take time to get from their base of operations to wherever you happen to be, and that time can be more than you can afford to wait if you have no means to take care of you and yours. Would you not be better off being able to care for a stricken individual until the ambulance arrives than just standing there doing nothing other than hope that they can tough it out? If so, then you believe in prepping.
So, what--at the minimum--should you prepare for? As above, first and foremost, weather and climate related disasters. You should be able to reliably fulfill your water, power and climate control needs for a period of at least one month. You should have food stores capable of feeding your household for the same length of time, at least one member of your household capable of handling injuries (including traumatic ones, due to accidents) and have a medical tool supply (not just a first aid kit) able to handle such matters. Household members on a medication regime should stockpile at least a one month supply of dosage. Extending this out to a full season (three or four months) is a good idea.
After that, you should consider that our global financial system is actually very weak and so close to collapse that one more major disaster could push it over the brink. A financial collapse will lead to political instability in short order, and--as I noted above--government agencies take care of their own first. You need to be able to protect yourself, your dependents and your property ON YOUR OWN. This is why you should acquire the means and the skills necessary to do so; in the U.S. (to varying degrees) this means firearms, ammunition and training in using them in a defensive way (because using a rifle to take game is not using a rifle to defend your house). While the popular image has preppers gearing up to take on the State, this is deceptive; the immediate threat are desperate and opportunist individuals or small groups operating as bandits, hoping to raid a store and take away the goods. In other words, common criminals and gang members. (After that comes paramilitaries--rogue agencies and militias--and then the State; the fantasy is the opposite of the most likely reality.)
(It is important to emphasize "defensive" here. The objective is to stop the attack, not to punish the aggressor(s); as soon as they disengage, let go and get out of there (if not at home) or batten down the hatches (if you are) and start fixing the damage. You are no good to your household if you're dead or otherwise unable to fight, so constrain yourself accordingly. I won't recommend what firearms you should get, or what substitutes you should go for if you can't or won't get firearms; that's something specific to where and how you live, and you know that better than I do, but I can refer you to others who focus on such matters if you want to know.)
I'm not, at this point, pushing for total detachment from the Grid. I'm telling you that the Grid can and does go down, in predictable and therefore knowable manners. I'm telling you that even the most well-intentioned and capable agencies of the State still have to see to themselves first before they can come to your aid. Because of these facts, I'm saying that you should be capable of securing yourself for long enough to easily handle those episodes when they occur- and, once you get that far, you should go a few steps further because there is an even worse--yet foreseeable--disaster on the horizon. Therefore, I conclude that prepping is a rational course of action that everyone should follow. The benefits of creating a far more resilient and self-sufficient community, composed of far more resilient and self-sufficient individuals, would far outweigh the costs in making ourselves so capable.
Which, in turn, leads me to a question: why does the Establishment want to convince the population that preppers are criminals-in-waiting and should be destroyed by the State?