A laptop packed properly in a hard bag full of clothes isn't very likely to take any hit, though. If the baggage handlers run over it by a truck, then it may be damaged, but not in plane.
(And considering the amount of carry-on luggage that people routinely bring in Chinese domestic flights, this is not surprising; there's a limit to what the overhead lockers can take, not to mention that pathetic slot where your feet should be.)
The business model is obvious, and has been tried at least once: http://qz.com/309185/this-startup-wants-to-pay-you-to-fly-wi...
A typical case is that we have software in development, I'm about to demonstrate it to a customer tomorrow, and before I leave for the trip, I'm making the final build and tweaking of demonstration data set at office and installing in the laptop that I use as a demo server.
By the time I'm ready, the DHL shipments for the day have gone and if I ship it, it would be there one day after my demo. So it has to be in my luggage.
Yes, checked-in luggage may also be lost and delayed, but with direct flights, I'll be fine as long as I'm not going to CDG (Paris).