In 1927, British filmmaking was still centred around smaller studios working with contracted technicians and in competition with the more dominant theatre world.
American cinema, however, was vertically integrated, meaning studios such as MGM or Warner Bros. controlled every aspect of the film production process, from talent scouting to financing to legal matters to editing. This resulted in larger studios controlling more of the industry while also managing to be more cost effective, and thus gaining a competitive edge.
British cinema, structured around small studios with equally small stables of contract actors, making quieter films on comparatively sparse budgets, couldn’t compete with the influx of more economically produced films featuring bigger stars from Hollywood, in which action and technical innovation, along with sex appeal and star power, were sure to draw audiences.
With films such as 'Red Ensign' (1934), directors like Michael Powell, who would go on to create such classics as 'The Thief of Baghdad' (1940) and 'The Red Shoes' (1948), were given a low-budget, low-stakes arena in which to test and develop their skills, allowing them to create films which are treasured today and passing on their knowledge to later generations of filmmakers.
So in 1927, Parliament passed the Cinematograph Films Act, which required British cinemas to show a fixed percentage of British films a year, made by British cast and crew, and paid for with British financing. Of course, good intentions go awry, and rather than boosting an ailing British film industry, studios began turning out short, cheap films which only barely met the requirements set in order for business as usual to carry on, all while they closer relations developed with Hollywood.
While these films were sneered at at the time, later generations have recognized the importance of having a recording of music-hall performances, for example, or potato harvests in Norfolk, or examples of early roles for actors such as Hermione Baddeley, later of 'Room at the Top' (1959) and 'Mary Poppins' (1964) fame, and Sebastian Shaw, who appeared as Anakin Skywalker in the original 'Return of the Jedi' (1983).
They provided work for actors and technicians during the uncertain interwar and Depression years, allowing them to both put food on the table and to develop their craft.
The Quickies themselves came to an end with the Films Act, 1960, but their value as a proving ground for actors and filmmakers continues to be felt today.