There is a more reasonable brother argument to could make, which is that we have well tested and effective drugs available today for managing cholesterol. Any new treatment would need to clear the bar of being better than those (in at least some circumstances) to be put into wide use. This bar may cleared by the fact that existing treatments often have adverse side effects.
Further, the one time treatment aspect is actually a demerit in some ways, as one cannot stop the treatment if there is an adverse effect. This means that the safety profile would need to be much better than us typically required. And proven over a longer timeline.
Of course, this is all concerns about approval and widespread deployment. We are still in the early human trial phase, where much more risk is accepted (subject, of course, to ethical guidelines).
Nothing about this treatment is targeting the germline.
Edit: Also, high cholesterol tends to become a concern for old people, who tend not to reproduce.
Do you think that such a drug should not be given to anyone who lost a limb due in an accident that was partly due to their own poor judgement because it was "down to choices made"?
Also, is there something special about gene editing that means it should not be used for these situations? Or if you go outside when it's icy and fall and break a bone, should the hospital refuse to treat you since that was your own fault?
Maybe substances that can trigger epigenetic effects would be more relevant to such things. I understand a Japanese team is working on a means of triggering tooth regrowth by means of an injection. I've got no problem with that. Or something like Skele-Gro from Harry Potter either.
That you don't label the specific phenotype a disease doesn't really matter.
What if the body raising cholesterol levels serves some purpose we aren't yet aware of? I've heard there's some evidence that medication to reduce blood pressure has a potential link to the onset of Parkinson's disease. Maybe messing with blood pressure in that way without addressing underlying causes has been a mistake, and messing with cholesterol levels without addressing underlying causes could also be.
Having said that, we have we been medically lowering people's cholesterol levels for decades, and the evidence seems pretty clear at this point that it is a net health benefit to those for whom treatment is indicated.
It is not at all obvious that targeted gene editing would be more disruptive to the body compared to flooding the body with a drug that happens to interfere with the one part of the process that we found a drug to interfere with.
Particularly if we are editing the gene to match a form that is already present in much of the population.
If medications can already do what's required for cholesterol issues, why wouldn't we continue to use them rather than making some change to affect a complex balance that could cause problems over very long timescales?
If we were to be editing a specific gene to match what the wider population has, then I'd be more ok with that.