This is a classic case of damned if you do, damned if you don't. IF she had posed "eating" a burger everyone would be screaming "liar".
That's absolutely false, and it is perfectly possible to skip a fast-food meal without making it the main plot of her social media presence that day.
TL;DR you could've come up with a better analogy
The analogy, firstly, was intended to make the point that Kelly's obnoxious behaviour is not warranted by an ethical or aesthetic standard, and secondly, is for that purpose decently strong. Your criticisms are largely in error, as rendered most transparently by your insistence that I compare Beyoncé to an actual burger or that Howard Shore is to her what Nobu is to In-N-Out.
The thrust of the analogy is this:
Roger Scruton and Kelly Gale both operate with (aest)ethical standards,
Roger Scruton exercises his taste in the Beyoncé concert (X) similarly to how Kelly exercises hers at In-N-Out (Y),
so X and Y are comparably obnoxious.
Your major issue, as I have come to expect from someone who tends to filter all information through the lens of privilege, is that In-N-Out is more economically accessible than a Beyoncé concert, which (though I fail to see it as salient here. practical reasoning being the pertinent issue) is easily remedied by displacing Scruton's behaviour to a slightly different scenario, e.g. a Beyoncé music appreciation group, which I'm sure is a thing. Beyoncé's music is very much aesthetically accessible though, so it holds on that count (whereas Webern is not), and palatable to an unsophisticated listener in a similar way to how the combination of fat and sodium in junk food appeals to the undeveloped palate of an unsophisticated eater.
It's also not the case, at least not according to Scruton nor any other aesthetician worth his salt, that Beyoncé simply isn't to everyone's taste, with the connotation that taste is not subject to qualitative differentiation. Good taste in art exists, just as some diets are preferable to others, and they equally express morality. If you decide to educate yourself on the former, I recommend Susanne Langer's
Philosophy in a New Key followed up by
Feeling and Form, but it's not a topic suited for haphazard engagement on a mostly deserted online forum.
Back to my intention, it was to render more understandable the backlash against Kelly by comparing it to a scenario in which our biases do not spontaneously interrupt and skew our judgement. The assertion that girls on SGF are likely to jump to Kelly's defence is uncontroversial, because most of us on here take a rather disenchanted approach to food and recognise some choices as superior to others, but not all people share our perspective. Their taste remains undeveloped and naive, just as popular aesthetic judgement does--and like we might say that Kelly shouldn't pretend to like In-N-Out etc. because the food is actually bad, so will the aesthetically more refined sympathise with Scruton's disapproval of Beyoncé. Both occupy morally defensible positions, which is why I don't think 'shaming' is an apt description, but being purposefully inflammatory is not consistent with that.