Ex-Microsofter explains why Windows 10 for phone uses hamburger menus
In a video that accompanies the AMA, the former Microsoft software designer explains the difference between iOS and Android, both of which which put a title bar on top flanked by navigation and action prompts, and the Windows Phone UI. The latter has used a side swiping navigation system with action prompts on bottom.
As our hero points out, horizontal navigation is not exactly ideal. "It's part carousel, part 'mystery meat navigation' and it just doesn't work. So. We needed to figure out what the new model would be." He also pointed out that there was no convergence with Windows 8 and Windows Phone 8 because of the lack of a top navigation bar as found on the desktop OS. But it is an easily fixed problem says the former Microsoft employee, solved for Windows 10 by putting navigation controls on top, and keeping the action prompts on bottom. And next to the navigation bar on top a hamburger menu is employed.
So that is why Windows 10 for phone has something in common with Android and McDonald's. Hamburgers. And by the way, even though our hero remains anonymous, Reddit has indeed verified his identity.
source: Reddit via WindowsCentral