Or maybe gamers at large just don't think Sony's software is that brilliant?
It boils down to this. As good as some of Sony software is ... its not resonating with the average Joe gamer. Those guys are buying Gears, Call of Duty, Halo .. not Uncharted, Infamous or Killzone. Granted, those 3 sell well, they don't sell as well as the MS portfolio and ... lets be honest .. outside of MGS4, I don't think Sony has released 1 single game this entire generation that has really granted them a sales boost to the point where the game could really, really honestly be called a 'system seller'.
Thinking back Sonys first month on a 3 month run where they outsold MS in NA was when MGS4 released. Every other major Sony franchise debut did nothing of the sort, and likely sold mostly to the already established Sony base who already owned a PS3. Everyone thought GT5 would do it, but that didn't happen.. at least in translated sales according to NPD.
I may be wrong, but at a high level I think the guy I quoted is spot on. Gamers, gamers just don't care enough about Sonys software regardless of how amazing it may or may not be. Nintendo sold well because its Nintendo and because of the Wii fad that was infectious. The 360 steamed ahead because of its Live infrastructure, and community built around that which brought attention to the platform and made it stand out. People bought 360s to play online with their friends and that meant playing gams like Call of Duty or Halo. Sony and PSN being free isn't enough (clearly) to swoon the consumer away from Live.. clearly consumers see Live has the superior service.. in both sales and subscription rates. A few bothered enthusiasts on GAF doesn't change that..
I think Sonys biggest problem this generation was their lack of buzz. Sure they have PSN.. but its no Live. Its no XBLA .. and it lacks a standard experience across all games that Live offers... with less features. PSN has come a long way, but even with the marketable FREE moniker attached to the service .. it doesn't matter. THe proof is in the pudding, and the numbers just don't add up for Sony. Software wise Sony has a great portfolio.. but apparently that isn't enough.
Looking forward to next gen, Sony needs to re-evaluate itself and figure out what it needs to do to stand out against the competition. Great games isn't enough anymore, its not the 90s. Services, infrastructure etc.. play key roles now and will in the future. Sony isn't going to be able to directly compete with MS against Live.. they have to know that. MS is unifying Live across all platforms, Phone, Console, PC, Tablet next gen, and Sony has no way to compete head to head with something like that. MS is going to sell a unified Live as a major deal and they know nobody else can do that. So what Sony needs to do is come up with ... something. Something that sets them apart from Nintendo, and something that sets them apart from Microsoft.
If they can't manage to do that, they're in deep shit. Great games are not enough.