User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-3547390-20150519153027/@comment-126761-20150519160054

Essentially, there is a point at which increasing the line length makes a page more difficult to follow. While there is a reduction in line length on larger screens, it's still longer than some frequently cited numbers on the web for ideal line length (over 100 characters).