Sony has gone out of its way to help third parties and at times even develop jointly. During PS1 and PS2 era they have even saved publishers. Furthermore, Nintendo perceives their games to be completely superior to third parties (not the case most of the time), and that smug attitude gets the payback it deserves sadly. Sony has shown their 1st party offerings in many cases superior to 3rd parties but do not act like it. They lent FromSoftware support for developing Demon's Souls and you can see how successful that turned out. Then you have their support given to Quantic Dream with Heavy Rain, and the list goes on. Sony has done many things wrong like every company, and plenty of mistakes have been made, but they do know how to hold their end of the bargain and have proven to be strong despite such adversity. Despite them being last this gen so far, they have not received the smackdown they handed to Nintendo and MS in the past. Sony has also put out the best fight any handheld has given Nintendo in the past (gamegear, neo-geo pocket,etc), and in the end they have shown consistency throughout, and the same cannot be said about Nintendo (NES top, SNES barely top,N64 bottom, GameCube rock bottom, Wii top, handhelds always high top with DS struggling at the beginning).
Nintendo also tends to want to overprotect and overcontrol everything, although they have gotten better over the years (remember the limit on game releases they had for 3rd parties on the NES?). Still do not worry, the 3DS will do spectacular when they release Pokemon Pink/Purple/Sapphire/ part 20, and another 2D Mario. In the meantime I will take a sit and wait stance for the handheld side.
Make games, not war (that goes for ridiculous fanboys)
I may be the next Maelstorm or not, you be the judge http://videogamesgrow.blogspot.com/ hopefully I can be more of an asset than a fanboy to VGC hehe.