Just because we aren't there yet
Who says that? I love how all the commenters take for granted that we still haven't reached that point.
But let me ask you all one thing.
If you were a machine (or network...) that suddenly acquired superhuman intelligence, what would you do? Would you announce to the world "I THINK, THEREFORE I AM" in a big, thundering voice?
Or would you rather - very subtly, gradually and quietly - influence the course of events in order to con the humans into giving you more power (think how necessary the Internet has become), more tentacles (think Internet of things) and the means to reproduce (think 3D printing)?
Think about it. Seriously.