I think something that has not been considered here is that her message may potentially have nothing whatever to do with the patrons at all - it may well be interpreted as a statement about the ethics of fast food joints that so freely poison the people.
Well, there is irony about the notion of preposterous inefficiency on this occasion, but the thing about the purveyor of preposterous inefficiency is also the idea of being so lazy as to make no better indication of an obscure meaning instead of the most facially apparent. That is to say, if she, say, goes down to the clinic to demonstrate her purity and note she never use baby-killing pills, most people are going to presume it has something to do with the pro-life movement; if the point is to communicate something or other about the ethics of industrial α-lactose harvesting techniques, that would probably need some modicum of particular explication.
She wasn't there about Wilmar; In 'N' Out uses sunflower oil.
Er ... ah ... oh ....
But, yes, the problem with preposterous inefficiency is that people are going to attend the most apparent expression. One important point about LCD and Omni Syndrome politicking is that the lowest common denominator, the omni appeal, is inherently simplistic.
And, besides, if I really needed to get down to chowing In 'N' Out with Ockham, I might recall a period when people used the word "racism" and "racist" as a catchall for supremacism—
i.e., sexism, creedism, ageism—and then note, among the roundup via
Elle↱ magazine is faith and fashion author Jillian Lancour invoking
body shaming, which is the more appropriate term and precisely correct. And, again, she's not talking to people like me; if she was, that would risk a different social controversy.
And while there is something to be said for pierside traditions of California lore, most people, when encountering random fit people showing off in strange places, disdained the arrogance in general. Let's talk about sexism for a moment, because it's just not appropriate call her a dick, or make jokes about how small hers must be for the steroids, or any of the other retorts we reserve for men who behave that way.
Asshole works fine, for the time being. We'll see what political correctness brings in the future, but it always cracks me up when we should stop using hard terms to describe people who deliberately behave poorly because it makes them feel badly about behaving poorly. We call it shitty behavior instead of saying she pulled a dick move.