Apple has low volume sales? You might have picked the wrong company for that example. Nvidia in the consumer market might fit, I would agree there.
In comparison. Android phones (in total) outsell iPhones because they are cheaper/more affordable. Sure Macs and iPhones may sell more than an individual non Apple brand, but collectively all together, the non-apple brands outsell Apple.
But it is certainly true that making high quality products doesn't necessarily mean low sales.