Why is reaching every corner of the phone such a big deal anyway? Speaking for myself, one of the biggest reasons I like large screens is that reading and viewing content is so much easier - I don't have to squint when I'm watching a video, or deal with awkward reflowing. Interface designers don't have to use the new real estate just because it's there, they can design touch areas that are well within reach, while using the new extra space for other visual elements.
>Why is reaching every corner of the phone such a big deal anyway?
It's a big deal because the upper left corner is where Android places notifications and thus you're likely to perform this operation frequently and in a number of contexts. Whenever you get a notification you're very likely to want to evaluate it (and possibly take action) as quickly and reliably as possible. On my Nexus 5 I can easily unlock, swipe down and swipe left or tap with one hand and very quickly as well. On my OnePlus One unlocking is fine, but getting to the top left corner is tricky, slow and unreliable when I'm using one hand, and two hands is not always desirable or practical depending on the context.
On my Galaxy Nexus you can swipe down on the entire top edge of the phone to bring down notifications. On the home screen you can actually swipe down anywhere to bring it down.
Sadly, even though interface designers don't have to use the new real-estate, they still do. Even Google is guilty of this - Google Maps has interface controls at the top and bottom of the screen. This is aggravated by the fact that Maps is one of those apps people tend to use while walking (or driving), specifically when two-handed use is most inconvenient (and just plain unsafe).Folks don't care as much if Facebook or Mail takes two hands because you're far more likely to be sitting down (or at least standing still) operating them.
