They do not have government charters, simply because they were in existence long before the U.K. government started to monopolize the granting of degrees. Edison Institute of Nutrition also exists by its own right. It is a legally formed entity whose articles include the conferring of degrees. Government control of education has the advantage of guarantying uniformity. That is also its major disadvantage.
Innovation is discouraged.
Government approved schools characteristically do not offer any significant level of training in alternative medicine, for example. A degree from EIN is legally valid. It is for you to decide where legitimacy lies. To do so, however, would fail to recognize the significant level of expertise that EIN graduates have achieved. Our standards equal or exceed those of traditional universities.