Final answer:
Richard Hoggart advocated for the flourishing of popular culture because it provides a meaningful reflection of societal changes and can democratize cultural expressions by incorporating everyday life's mass media into art.
Step-by-step explanation:
Richard Hoggart, a prominent cultural theorist, wanted to see popular culture flourish because he understood its significance in reflecting and shaping social norms and values. Observing the surge in social mobility and the influence of American media in postwar Britain, artists like David Hockney and groups like Pop Art in New York saw an opportunity to create art that resonates with the common man and reflects contemporary life. Hoggart would have recognized that popular culture's reflection of the postwar era through mass media, advertising, and consumer tendencies provided meaningful insight into societal changes and attitudes. These artists sought to connect with audiences by incorporating the familiar imagery of mass media into their works, thereby challenging traditional fine art with their new meanings. This was a radical shift from traditional values towards a more inclusive and democratized view of culture and art.