Whether this is a convincing argument or not aside, I came across an answer which I find more appealing and which seems to fit the disaster genre better. The answer came from Zizek's The Ticklish Subject (Verso, 2000) which I was reading at work. As with most of Zizek's writing, I'm not sure if I have interpreted this passage correctly since I have only very minor exposure to Hegel. However, I will try my best. Zizek begins the section by describing "stubborn attachment", a term from Hegel's Phenomonology. According to him, it "stands for the pathological attachment to some particular content... scorned by the moralistic judging conscience" (121). Simple enough: Wichita and Little Rock are pathologically attached to the idea of Pacific Playland and "conscience" tells us that this is bad (i.e. our reaction when watching, especially on multiple viewings). Wichita even admits to Columbus (Jesse Eisenberg), "I know this Pacific Playland thing is nuts, but it's been so long since she got to be a kid." Here we have a perfect example of fetishistic disavowel: I know very well (that something is not the case), but I still believe (that it is the case). On the other hand, Hegel (via Zizek) actually thinks stubborn attachment is (or could possibly be) a good thing:
Such an attachment is the ontological a priori of an act - the hero's (active subject's) act by means of which he disturbs the balance of the socio-ethical totality of mores is always and necessarily experienced by his community as a crime... [W]hen, irrespective of circumstances, I stubbornly attach myself to some accidental particular feature to which I am bound by no inner necessity, this 'pathological' attachment enables me to disengage myself from immersion in my particular life-context... The paradox, therefore, lies in the fact that I can arrive at the Universal-for-itself only through a stubborn attachment to some contingent particular content, which functions as a 'negative magnitude', as something wholly indifferent in itself whose meaning resides entirely in the fact that it gives body to the subject's arbitrary will. (121-2)
With Zizek, "act" is always a loaded term with more significance than any simple action. An act for Zizek is "an 'immoral' lie which answers the unconditional call of duty, enabling the community to start again from zero" ("The Act and its Vicissitudes") or, as in the quote above, a "crime" to the community which disrupts the "socio-ethical totality of mores" in order to create new socio-ethical regulations. An act, therefore, is always something that doesn't quite fit within the symbolic order, which in fact ruptures the symbolic and allows the community to create new symbolic rules. In this case the "crime" Wichita commits is breaking her only rule with Little Rock to "trust no one, just you and me" and trusts (albeit temporarily) Columbus and Tallahassee. The fact that her stubborn attachment happens to be to Pacific Playland is unimportant because it "functions as a 'negative magnitude'", its only important lies in the fact that it embodies her will. When confronted with the choice to leave Columbus and Tallahasee behind, Wichita temporarily wills away her ethical stance of trusting no one in order to create a new community. This act, however, is not enough. Later on she confronts the Real of her desire when she and Columbus are drinking in Bill Murray's house and they become somewhat romantically attached. The next morning Wichita and Little Rock leave without Columbus and Tallahassee and the community that had been formed is disbanded.
It takes a second act, this time on the part of Columbus, to truly form a new community. At the very end of the film Columbus commits the "crime" of violating his rule "Don't Be a Hero" in order to save Wichita from a zombie-clown. This act reunites the four heroes and allows Columbus to realize "that those smart girls in that big black truck and that big guy in that snakeskin jacket, they were the closest to something I had always wanted, but never really had: a family... we had each other. And without other people, you might as well be a zombie." While this initial failure of Wichita's act followed by Columbus's successful act may seem to shed an unfortunately anti-feminist light on the film, what is actually at work here is Hegel's "negation of negation":
The inner logic of the movement from one stage to another is not that from one extreme, to the opposite extreme, and then to their higher unity; the second passage is, rather, simply the radicalization of the first... '[N]egation of negation': its matrix is not that of a loss and its recuperation, but simply that of a process of passage from state A to state B: the first, 'immediate' negation of A negates the position of A while remaining within its symbolic confines, so it must be followed by another negation, which then negates the very symbolic space common to A and its immediate negation... Here the gap that separates the system's 'real' death from its 'symbolic' death is crucial: the system has to die twice... The passage from In-itself to For-itself thus involves the logic of repetition: when a thing becomes 'for itself', nothing actually changes in it; it just repeatedly asserts ('re-marks') what it already was in itself. 'Negation of negation' is thus nothing but repetition at its purest: in the first move, a certain gesture is accomplished and fails; then, in the second move, this same gesture is simply repeated. (79-83)
Thus it is not simply that Wichita's act fails, her act is necessary for the complete elimination of the old symbolic network (of distrust). "The system has to die twice", and Wichita's 'failed' act simply bears witness to the first of the system's two deaths. In order for the new community/symbolic to become "For-itself" the old community/symbolic must die twice, the first time when Wichita betrays her rules of trusting no one for the sake of Columbus and Tallahassee, and the second time when Columbus betrays his rule to not be a hero for the sake of "family" (i.e. community).