Your flaw is in assuming that tablet + keyboard == laptop. Tablet + keyboard is way better than a laptop in some contexts, way worse in others. Imagine being an illustrator that also does a lot of communication with clients over email. Imagine being a blogger that writes articles but also touches up photos. Imagine being a mobile software developer, writing and testing code on the same device. Hell, even mobile websites are a huge market today and they're all interacted with via touch, most mobile web developers should actually be moving to tablets for testing.