Are you talking about just Sony consoles? Because otherwise your observation is false: Microsoft Xbox One, for example, got an upgrade from DVD to BluRay as same as did Wii. And in previous generations both did not get any upgrades.<p>The reason Sony upgrades media on its consoles is that Sony is a holding that also holds companies developing the said media and companies distributing movies&#x2F;music on the same media. It&#x27;s a cross-promotion.