Frankly, if one can't see the applications for tablet PCs even within the home, much less its countless business uses, I don't think they have a valid opinion worth listening to beyond "because I just don't like them" which is fine, but not really a convincing argument why nobody should use them.
The battery life and "always on" nature of tablets like the iPad alone make it useful in many places where laptops simply aren't. Passing around a laptop to show a client or co-worker a document or graphic is a lot more awkward than handing someone a tablet. If you don't always carry a laptop around in sleep mode, it takes considerably longer to boot up, locate your document and then load the appropriate app, even if you have a laptop with a SSD boot drive. Access to your data is available much faster on a tablet due to the simplified UI. There will never be a laptop or netbook with better, more efficient power use than a tablet.
The only area in which tablets fall short is in straight productivity apps, which most are keenly aware is NOT the point of tablet PCs.
