They aren’t getting bored (although they do have a short attention span, which is why they like “twitter” with it’s 140-character limits, and Tumblr where they just “reblog” stuff from other people with single-line comments).
What they are getting is mad. They are mad at the invasion of privacy. They are mad that Facebook makes them jump through hoops to get notifications from their friends and from businesses they like (having to build interest lists).
They are mad that Facebook spams their friends with e-mails saying that they are “following pages”, and showing advertising pages falsely implying that they are following THOSE pages.
They are mad that Facebook has started turning their system into a for-profit enterprise.
And they might like Instagram now, but wait until they figure out that Instagram has claimed full usage rights for EVERY PICTURE that you post, including for advertising or sales purposes. In other words, you post an Instagram picture of yourself, they can sell it to an Ad agency, who can use your picture in print media somewhere without your knowledge.
But are they mad enough to tell Zuckerberg to go scr!w off?