Its because new customers won't be affected by the psn issue other than no online for a week or two, and they probably think since it happened once sony will do everything in their power to prevent it from happening again. PS3 is also by far the best value in terms of price. Just think about it for a bit.
msrp prices
PS3 price changes $499/599->$599->$399/499>$299/$349 In total PS3 has gone down in price $200-$250 in price from launch with a 100-260gig improved harddrive and removed backwards compatibility.
Wii price changes $250->$200 In total Wii has gone down $50dollars since launch with no significant changes that im aware of.
360 price changes $299/399/->$349/$279/$449->$299/199/399->$199/299 In total 360 has gone down $100 dollars in price from launch with an added 4gigs flash memory, or 112gig improved harddrive, and wireless wifi.
People are too often running around claiming the ps3 is owning even while being the most expencive. It is ridiculously low priced compared to its competition for the tech inside of it. Its like showing off that a 1080p 3d lcd tv with free cable for life, is outselling a 720p plasma tv with a $60 suscription, and a boob tube tv from over a decade ago, when all of them cost within $100 of each other. There is a reason sony is making the least amount of money from its gaming divison by a huge margin despite having steller software sales over the past few years. It has been forced to cut prices far more than its competition.