User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-452-20150521172949

A general response to many complaints:

If you: Why aren't you simply setting your preferences to use Monobook?
 * are seeing Desktop XL and are complaining about the reduced width,
 * are asking for an option in your preferences, and/or
 * do not care how your layout looks on smaller screens
 * Monobook has always had the widest content width, and is unaffected by these changes.
 * Wikia often update Oasis, but rarely update Monobook.
 * If you want to take advantage of your high resolution monitor and ignore what other users see, then Monobook is the obvious choice.