I think there are two seperate issues we shouldn't mix up: On the one hand Apple is moving at such a quick pace, that there is less time for quality control, and many bugs stay even between major releases.
On the other hand Apple has never been good with networking software. For example, File Sharing is slow and used to be very unreliable. The built-in FTP support in OS X was a joke. Sending files with iChat on AIM often failed. Mobile Me was never really successful. More recently there is FaceTime, where my Mac just randomly fails to connect. Every time I synced bookmarks with iTunes between Safari on the Mac and on my iPhone I ended up with duplicates on both devices. And now we have iCloud syncing, which is incredibly unreliable.
On the other hand Apple has never been good with networking software. For example, File Sharing is slow and used to be very unreliable. The built-in FTP support in OS X was a joke. Sending files with iChat on AIM often failed. Mobile Me was never really successful. More recently there is FaceTime, where my Mac just randomly fails to connect. Every time I synced bookmarks with iTunes between Safari on the Mac and on my iPhone I ended up with duplicates on both devices. And now we have iCloud syncing, which is incredibly unreliable.