Apple releases "Retina Display", with ultra-high resolution: "Amazing! So much better than anything else! So crisp! So beautiful!"
Someone else releases lower pixel density display for laptop, but far better than what Apple deigns to offer: "Ugh! No! How can you read that? That just gives you eye strain..."
Right, but most icons do not exist in a high resolution format yet (as far as I know, I would appreciate if somebody to correct me on this, if I am wrong).
Apple's retina display works because they have graphics that are the same physical size on screen. When I switch from my MacBook Pro display to an external Samsung display, the icon and text both get smaller.
(Exaggerated for emphasis)