Wouldn't that just make them literally a hotel chain, with no disrupting difference to any any other? I'm fairly sure I can book a room online at the Hilton.
Even funnier, because most of the brands don't even own most of their branded hotels, they're usually franchised. Hilton/Marriott/Starwood/Choice/Wyndham/Accor collecting 5% to 15% is basically the same thing as AirBnB is if you're not using someone who actually rents out part of their home.
Concur with imjared -- Uber likewise went "full circle" and started adopting more "cab company functions" once they reached the appropriate scale: "Oh, hey, we might as well make money leasing the cars too!" "Oh hey, there's money to be made in payday advances!" [1]
With that said, (per imjared) Airbnb may have some comparative advantage in the ease with which they bring this spare capacity online via a nice interface; it could become a useful platform for allowing hotels to dump extra rooms for sale, in a way that's more pleasant for users to find.
[1] Lyft lets you get paid earlier for 50 cents IIRC.
AirBnB already owns the touch-point with customers who are looking for non-traditional places to stay. Some portion of those customers would also be open to normal hotels, and AirBnB could serve them by doing something as simple as adding another check-box in the "home type" interface. Once word got out that you can do both things in one place, there would be little reason to go through any other service and they would take an ever-larger share of all bookings. Of course, this is won't happen, because hotel operators, seeing this danger, will refuse to integrate with them. But that huge market opportunity is still there, they "just" have to build their own hotel capacity to realize it.
Correct but hotel booking process is quite diverse and all the means I have tried are fairly painless. You can call the hotel directly and book a room. You can check one of many online sites and book through them.