Selnor : The 3rd place is not "secured" at all for the PS3 according to recent sales numbers. MS could "secure" it later for its 360, nobody knows right now.
The PS3 installed base lagging behind was more an effect of releasing 1 year after its competitor and at a much higher price than anything else. It let time to the 360 to install itself as the only 'next gen' console, a big blunder by Sony obviously.
Good games were not the deciding factor, there were already some in the first PS3 years, although it only started raining great PS3 games in 2008.