The narcissistic services like Twitter and Facebook haven't really had a video equivalent. By limiting the videos to 6 seconds people will be able to post little videos without requiring the talent or effort to make something longer that people will be willing to watch.
Just as the reddit front page has become dominated by meme images that require little brain power to consume, Vine will ideal for LOL videos posted by people. I suspect it will be very successful.
Also, the OP says "Instagram makes everyone ‘creative’." Seriously?