Now why is it that they only peddle their merchandise in America even thought they are located in the UK?
Because it is a violation of UK law for them to sell their bogus diplomas.
The Education Reform
Act 1988.
214. Unrecognised degrees. — (1) Any person who, in the course of business, grants, offers to grant or issues any invitation relating to any award—
(a)
which may reasonably be taken to be an award granted or to be granted by a United Kingdom institution; and
(b)
which either—
(i) is described as a degree; or
(ii) purports to confer on its holder the right to the title of bachelor, master or doctor and may reasonably be taken to be a degree;
shall be guilty of an offence and liable on summary conviction to a fine not exceeding level 5 on the standard scale.