These are all good points and very few if any ‘reviewers’ address a lot of these.
Basstheworld almost always gets the products to test, but if you listen and watch Gregor carefully, he tells you (or does it with his humor or eyes) if something is amiss. But no one can really go too far who gets product, or no one will send them product, as we all know.
The quality issue is a tough one becuase there is varying quality across everyting, you can get a lemon of a car, a dog, an anything that sat right next to a perfect one. Quality is measured across a manufacturing run, not in one offs (unless of course you are the consumer). I know a single bad QC (or multiple in @akos’ trouble) can put off a consumer for good.
I like @Old_Noob’s approach about looking at design build overall and how it relates to quality like the sheilding comment, etc. However, most lower end stuff has little to none, etc.
My first Squier 70 CV Jazz had no shielding, no hum issues, etc. Neck is as solid as they come. Had a mid range LTD with hum issues (sold now) with top notch Aguiler pickups and electronics had loads of hum, we well sheilded, etc. It has put me off a bit on Aguiler, but I also wasn’t nuts about the tones.
I think quality, since it varies across a line/brand/etc, along with personal experince makes for a very subjective vs. objective view of things, unless its rampant. I owned a Range Rover. I can tell you the car was amazing look/feel/drive/etc and the quality sucked bad, still does, and people still buy them and almost wear the bad quality like a badge. Go figure.