How is this any different from seeing your messages or mail scrolling across the notification bar. Where you might get a snippet. I can stay in the app I'm in and read the entire message as it scrolls across the notification bar or just choose to read a few lines and attend to it later. Sounds like the same thing if not less functionality to me.
That's the funny thing about preference...
Furthermore, your assessment is inaccurate.
I have an iPhone 5 and GS4 on my desk, and both have the Google Hangouts app open, having a conversation with my wife.
I send myself a test email from work.
All the GS4 gives me is a status bar pop that says "2 Messages"
The iPhone 5 gives me a banner with the name of the sender, and the subject line of the email.
Not even close as to which is more informative.
On the home screen, the iPhone 5 has a badge on the icon telling me there is an email as well. Easy Glance and go without giving up a big chunk of screen to a widget. With the android status bar badge, it could be 1 email or 100 waiting to get addressed.
And in notification center, with iOS I can go directly to the Gmail section and I can see the subject line, date, time and sender for each individual email. I can go directly to a specific email in gmail as well from notification center.
Android's notification just shows "3 new messages", the sender, and subject line, but it's crammed between the Google Now sports info for the Yankees and a Google Hangout notification rather than being intelligently cataloged.
With android I also can only go to my gmail inbox, rather than directly to an email. This is a problem because it clears the gmail notifications, so I can't leave things in notification center like a de facto "to do" list.