Hitachi -like many companies- made other products of course, but again like many others, they kept their ranges slim. It may have appeared that they did many different types of cleaner, but in fact they must have only had about six on sale at any one time. After the original Cv-50 upright, Hitachi always sold a standard, autoflex, and autoflex-electronic upright, but that was it. The cylinders typically comprised two or three bagged cleaners, and a bagless alternative, but never anything over the top or very expensive.
I suppose Hitachi saw a place for a vacuum cleaner bearing their name in the UK market, but played it safe by limiting the ranges and keeping prices low. Moulinex did exactly the same, as did Goblin and, not withstanding price, Electrolux, for a good deal of years. It is a very sensible strategy in many ways.