I've recently watched someone browse the web and I was surprised to see Google's welcome message that announces the new navigation interface. If you don't hide the message or click the grid icon, the message is displayed every time you use Google. Apparently, the person next to me used Google to search the web, but he wasn't curios to check Google's app launcher.
Since the new app launcher is hidden, it's likely that less people used it than the old black bar. Google Trends shows that the search volume for queries like [google docs], [google drive], [google news] or [google calendar] increased a lot in September, when the app launcher was released. If the links at the top of the page are missing, the search box saves the day.
Here's a Trends chart that shows the US search volume for [Google Calendar] in 2013 and 2012:
{ Thanks, Jérôme. }