That's like saying beware of eBay, check out Amazon instead... If you are an eBay user then you should be buyer beware and internet savvy, apply the same rules to airbnb and you will save a fortune.
Airbnb is a recommendation site, you can see the rooms / apartments that have had previous bookings, comprehensive ratings, loads of pictures and you can speak direct with the owner. It's massive in the States and is growing in Europe.
The protection other sites offer is only relevant at the start of the listing and is as open to abuse as any other online purchase. Airbnb also holds the money which is released to the property owner near the end of the customers stay.
PLUS - verification of ownership is taken before a listing is completed - driving licence and passport images uploaded to their database.