Firstly, that's a very simplistic view - there was a whole bunch of software responsible for creating the DS wave of positivity including mario kart, castlevania, animal crossing, phoenix wright - a wave of new-meets-old which got everyone excited.
Secondly, the DS added the features you mention to a handheld. To add them to a home console, allowing for the user to interact with games even when 'off' or when your wife is watching TV, permits a lot more engaging online games/persistent worlds, allows for players to remain connected to their home system when usually they wouldn't be able to, and this connection will breed good feeling towards the console and desire to use it more.
It's the 'good feeling' which is required to create the boom in console popularity, as with DS, and Wii (and the lack of it is a contributor to what has since damaged Wii amongst certain areas of the gaming community).
Microsoft let me view my friends list on xbox.com and see who's doing what, but if I could do that on my controller, effortlessly, I am much more likely to do so, and therefore less likely to miss friends when they are online. It could be achieved through a text-messaging service to my phone, also, but having it on the controller and the capability of playing with them there and then is significant.
It'll be like... a cafe... where all my friends hang out, come and go, and interact with me!