Sega was already pushing gaming into the more cinematic/violent/teen-centric direction, so Sony really didn't start that.
What Sony does is they simply make no-nonsense consoles -- powerful hardware with strong third party support and then sell them for a reasonable price. With solid marketing behind it.
Then they wait for their competition to screw up. Sega/Nintendo/Microsoft all repeatedly shoot themselves in the foot every generation, which makes it easy for Sony to dominate. Using a tennis analogy it's like a tennis match where one player keeps making unforced errors ... it makes it very easy for the other player to win the match.
The only exception was of course the last console cycle, but really think even there it took a controller miracle from Nintendo and Sony starting at $600 freaking dollars and even *still*, the PS3 is going to end up very close to the leading Wii's LTD by the time its discontinued.
That means even when virtually everything goes right for Nintendo + MS and a lot of things go wrong for Sony, Nintendo/MS can still barely win.
3/4 last generation generations (so basically the last 20 years or so), Sony has dominated fairly easily. In hindsight really "winning" the console wars is less about miracle home runs and more about whoever makes the fewest mistakes.
Looks like we're headed towards a
PS4: 90-100 mill, XBox 1: 40-45 mill, Wii U - 18-20 mill
generation.
