I never complained about the build quality. The build quality is amazing. What I am talking about is something you hold, starre, it should make you feel like a premium device.
Example. Almost a decade ago Nokia launched a DUMBPHONE!!! Nokia 8800 and 8600 Luna. It was a dumbphone and nothing compared to, that time's king Nokia N95. Buy the kind of quality material, that was used was not only a tough material, but a premium look and feel, which one would love to hold and starre.
Similarly, HTC One M8, might not be tough as Lumia 920, but its premium material like the panel, the way one feel pressing the button, holding it in hands etc makes it feel like a premium device. Even HTC One Desir 816, which is made up of cheap plastic, looks like a preimum device compared to Samsuck.
I never doubt the build quality of devices like Lumia 920, 1520 etc. But they can further give a premium look and feel without compromizing the build quality.