There are a lot of components involved, it's true, but one of the most important catalysts for all other components is differentiation. A product which sets itself apart from its competitors can also draw in other demographics than the competitors do. More demographics means a larger user base. A larger user base means more games made. More games means more hardware sales, fueling refinement of that hardware and reduction of price for making it.
Products which do not differentiate themselves do not have a significant impact on their competitors. Though this can be combatted with secondary measures (such as having a larger distribution base than your competitors and aggressively marketing to get an early lead), it ultimately becomes a battle of attrition. The product which came first maintains its market stronghold by virtue of inertia, while the undifferentiated product fails to make a noteworthy dent. This applies to software as well, and is a big part of why no MMORPG which uses the World of WarCraft model has triumphed over World of WarCraft in terms of subscription base.
As for if Sony would risk innovation, they're not in a position where they'd be willing to. Large companies fear loss of resources more than small companies, and a failed attempt at disruption can sink a company. They will all but universally opt to take the safe route of improving what's already there over attempting to establish a new market and temporarily (if successful) or permanently (if not successful) alienating their existing demographic in the process.
Sky Render - Sanity is for the weak.
