Counter-argument: the PS4's desktop is the one place where performance least matters. But they would like to add new UX features there, over time, with less dev effort. Especially basic UI content. That can be fetched remotely or locally, relatively seamlessly. Which is what browsers already do well.
It bothers me how little people care about responsive UI. I haven't used a PS4 yet, so this is more just a general comment than a criticism of the decision - but the PS3 is a bit of a clunker in its cross-media bar. There are spinning placeholders for a couple of seconds every time the icons load. It doesn't exactly scream raw power - why aren't devs embarrassed by these things?
FWIW, Ars' follow-up review of the PS4 talks about how there's still loading indicators in the main menu UI's, which should not happen IMO when you're essentially talking about icons and you have 8GB of RAM to work with.
The issue with the PS3's UI is that it's seen a marked increase in complexity since the initial release, coupled with less resource access. As it stands the PS3's XMB has access to about 80mb of RAM, the rest is reserved for games. Also everything I've heard about the PS4 makes it sound like the UI is incredibly fast and responsive.
He's right, though. On the PS4 desktop, you're not having 10s of thousands of particles that interact with each other being rendered at 60fps. You're not going through 100 passes with different shaders making the perfect experience.
You're having maybe 1000 particles or a 50,000 polygons. Much lighter weight. It doesn't /need/ the performance that a game does.
When the PS3 isn't running anything, the icons don't spin or need to load in. When in a game or app, however, they do. Why? Because the majority of CPU and memory is reserved by the game; the icons will not be in memory; you have to async load them and the game might be using some streaming resources.
Wait, why doesn't performance matter on the desktop? What happens when you hit the PS4 button (or whatever it is) in a game to bring up the UI overlay? What happens when you're in the desktop itself, panning around? What happens when you install updates? Do we have to sit through flickering screens as update after update is installed?!
Interface performance is really fucking important, and I sure hope people like Sony and Microsoft care when it comes to their consoles.
People like EA and the notoriously terrible Battlefield* interfaces obviously do not care. (The original Battlefield 1942 would switch from your native resolution and refresh rate and color depth and put the screen in 800x600 16bit 60hz every single time you hit the escape button.)
The performance of the desktop on the PS3 and PS4 is less important to the gamer than the performance of the games, also known as the primary purpose of the device.
However, that doesn't mean that it is unimportant.
> the PS4's desktop is the one place where performance least matters
Performance in general still matters a lot on the PS desktop. Case in point, my PS3, which takes a godawful amount of time to load all the screen icons.
It's not like any of that is difficult to do when your ecosystem is closed and you are the only one in control of it regardless of how you decide to execute it.
And (memory) performance is of critical importance if the PS4 supports multitasking such as the Xbox One does (don't know if it does).
