Contractors a paid by the hours they work, so it is clear that any task that is assigned to a contractor will never be accomplished in under an hour. The reasoning being that one hour give less income than sixteen hours. To make it worse, I have noticed man-made complexities, to the extend that even the obviously simple task ended up with pilings of documentation justifying that it could not be done and hence it took many hours and the hours must still be paid anyway.
Another point is that, if a contractor completes all the work that means there will be no more new work. Take for example a web service. If a contract has to create ten services, if he/she completes all the services in 3 months that means he has to be on the market again looking for another contract. This is not very difficult to realize. It only takes one or two contracts to realize that you don’t want to be looking for a new contract each time, especial in a time of global recession when may companies are cutting costs.