User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-4189499-20150520014724/@comment-5558012-20150520023801

"By making the width the same, editors on medium-sized devices can know that their edits won't look like crud on larger screens."
 * I really liked how Wikia was before fluid and I'm glad they are going somewhat back. Large screens tend to make the articles I create have way too much white space.