Our individual thresholds for quality differ, that's for sure, because my definition is "Was the object built well, considering it's constraints?" As an example,if something is made of plastic (or "polycarbonate"[1]), I expect it to flex to a degree, and it can still be very well made (e.g. old school Nokia phones had incredible build quality and industrial design)

1. I hate that plastic had to be re-branded in this manner because a small-but-vocal contingent decided it "feels cheap" on phones, or somehow lowers build-quality. This resulted in glass-backed phones which ironically had to be kept in plastic cases to take advantage of plastic's superior elasticity.

The correct quote regarding the hinge is, "the hinge doesn't feel as strong". "as strong" doesn't mean it isn't strong. It means the original commenter doesn't think it is as strong as another hinge not that it isn't strong. Since there is no data regarding actual hinge performance this is a subjective and not an objective evaluation. Keyboard feel is also very subjective, so one person saying the keyboard is "mushy and creaky" holds no real value either.