User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-2126441-20150519125912/@comment-126761-20150519140546

While it is thinner now, consider how it looks (and has always looked) for those on smaller screens, like tablet devices. This is one reason why it can be desirable to have a more consistent width across devices - so that editors can design for one width, and not end up breaking the experience for a large proportion of visitors.