Remember when you could load up all your IM accounts in one program?
ICQ, AIM, Facebook, MSN/Windows Live, Jabber etc..
Now things are going back to the silo - and sure, you can install the individual apps, but they're bloated hogs that want to be the default for everything... and on mobile, it's even worse - I mean, why does Yahoo need to keep video/audio call support going in the background even when you're not logged in!?
Clearly they want to bloat their competitors out and force people to pick their favourite.