Work permits for loan between English clubs

Why on earth does a new work permit application need to be made for a non-EU player with work permit with an English club to go on loan to another?!? :confused:

I don't know whether that's the case in real life football, but it's certainly not the case in other industry. Initial application need to be made with a particular employer, but once granted that person have permission to work until certain date. As long as he or she is working, the authority have no problems with changing employers.