PS2 launched a year earlier and had a successful predecessor. Xbox and GameCube all launched late. That's just one of the reason. Another thing is that PS2 can serve as a DVD player while NGC couldn't, Xbox needed to buy a license.
PS3 was a huge loss against Xbox 360. The reason that PS3 eventually caught up was Don Mattrick not PS3 itself.
The performance delta might be "17%". However that's critical to today's customers. That's why both of the big two are trying their best to achieve a high teraflops count. High bandwidth of SSD & clock speed means nothing but higher thermal generation and higher cost. In no graphical scenario that a faster chip can outrun a wider chip, under the same architecture.
That sure is some revisionist history considering the highest sales of the 360 were during the Kinect era -- 6-7 years into its life.
Say what you want about Mattrick's handling of the Xbox One, but he made the last half of the 360's life an even bigger success than the first half.