The whole point is not to limit the school. It avoids a duplication of sorts. If you are not happy with the company selection, then maybe you should be allowed a hand in the selection. That way you wont turn back on your selection and allege things you didnt see while making the 'professional opinion' on who you want to bring on board. Allegations such as those made here about flying not being 'in the blood' would not arise.
Simply the school selects who it really wants to train and it better deliver.