Battle tactics, their board of directors see the rise of other social media platforms that reward their users. What they are trying to do is to reduce the visibility of those new ground breaking platforms. Facebook is lagging behind, they only have the numbers, people who still use it daily don't really know what is going on elsewhere. What they are showing is fear of something better and are trying to maintain their stock price by keeping everyone else in their bubble of ignorance.

There are lots and lots of ways to attract a new audience, for example youtube, twitter, twitch tv, linked in, newsplatforms etc.