Thorsten Heins ''Tablet will be useless for five years''

Blackberry CEO Thorsten Hein  is of the opinion that tablets will be useless for five years. He believes Tablet business is not a good fit, and so therefore, the firm won't venture into it. He backed it up with a claim that Blackberry will rule the mobile computing world in the next five years.
Guys, remember this same gentleman said last year that the company new operating system Blackberry 10 will obsolete the laptop for three years. I wonder how he can be so sure about this.