How does clumsily being able to replicate a very basic task that laptops have been doing for many years extremely well for $100 imply that tablets are going to

How does clumsily being able to replicate a very basic task that laptops have been doing for many years extremely well for $100 imply that tablets are going to kill computers? This might well be the case (I hope so!), but being able to attach a keyboard is not the indicator of change this guy wants it to be.