As an aside, when i was in grad school, the style coming out of yale and the werkplaats typografie was this severely default design aesthetic. Times new roman massively overlaid atop a xeroxed image at times abandoning legibility. It was like high-art zine culture blended with dutch sensibility, i.e. http://ffffound.com/image/d6f63117fcf5ea64c59c66b8af85e2389d...
But to the point about what makes arial "good" or "bad" is the same thing that makes Didot a bit tough as a text face (it just wasn't designed to be used that way). And same with arial, it was designed as a screen font that prints ok. I don't think the whole "lesser helveltica" claim is entirely fair to arial, but you have to accept it for what it's for: a generic screen font. If that is the look you are hoping to rock, use it wherever you want.
And to the larger point: all prescriptive advice should be treated like training wheels. if you already have the sense to know what you're doing, you can safely avoid the advice. if you don't know how to critique your own work, then it helps to think about what the prescriptive advice is getting you to avoid.
If you are at the point where you are making intentional decisions about what your design should look like, then keep on keeping on. But it helps to be aware of the cultural baggage that those choices bring along with them. I critted somebody's poster once and made the offhand comment: "oh, that looks computery" and i was basically trying to say "that has that homemade camcorder feel that home movies have, but if it were a poster that had been made with a computer." and it turned out after some period of time that i was actually reacting, subconsciously, to the fact that it was set with arial. How weird is that? But it was because i was so familiar with that look as something that tasted digital that is seemed weird in print. It wasn't wrong, it was just giving off that vibe.
Likewise, butterick is trying to make his own mark, setting his own tone. That's his right, he's alluding to certain traditions and aesthetics. It's fashion, yes, but it's also all the choices and feelings that those fashion choices bring along with them.