Off-site on shoring

I work in IT as a programmer. It is a job I love but work is becoming scarce and this is in part due to those very clever Indians. I don't have a problem with work being off-shored, moving production to a place where it can be done cheaply with no loss in quality is an obvious business decision and anybody who finds capitalism acceptable cannot argue with that. However, there is another aspect to off-shoring called on-site off-shoring. To give a parochial example, assume that Acme Business Solutions has a need for a team of programmers. Acme Business Solutions contracts Indian Outsourcing Ltd to supply the programmers. The key element of the contract for this example is that Acme Business Solutions insist that all the work is done on their premises due to the confidential nature of the data the programmers will be exposed to. Consequently, Indian Outsourcing Ltd move a team of Indian programmers to Acme's premises. In order for these programmers to work legally in the UK they are issued with what are known as intra-company visas.
So far, so ordinary; I would be surprised if anybody in the IT sector wasn't aware of this happening. What I wasn't aware of until I heard Radio 4's File on Four (website here, transcript here and listen again here) last night, was that intra-company visas should be used where staff have specific company knowledge or distinct skills which were not available in the UK. According to Keith Sharp, marketing director of the National Association of Software and Services Companies (NASSCOM*), "Government guidelines are very clear that there can be no cost advantage in bringing in an Indian IT professional on a temporary assignment as opposed to a local contractor." In other words the Indian IT worker should be paid the same as a UK based contractor. According to Ann Swain, head of the Association of Professional Staffing Companies, there are "about 35,000 IT professionals coming into the UK frankly in a market that is not short of IT professionals in the incumbent workforce".
All of which leads one to ask the question "If it is not a cost saving then why are companies doing it?"

* An Indian Chamber of Commerce that serves as an interface to the Indian software and BPO industry.