Clearly, Humanities are concerned with understanding while the Sciences look for explanations – but the different focus can neither be reason nor excuse for a separation in disjunct categories of culture.
The real difference obviously is the different public appeal, the difference in popularity. While humanities can be chatted about even without deep understanding – just as a piece of music can be enjoyed without any understanding of an underlying theory – this is impossible with science. There can be Pop-music, pop-Humanities but no Pop-Science.
Rapoport and Hucho describe two levels of access to both cultures: the emotional approach (which they call vegetative) and the learned, theoretical approach. While the hard sciences lack the first, popular culture is based on it. The consequence must not be to popularize the hard sciences to science-pop but to insist on the deeper levels of understanding also of art and humanities.
Otherwise what is meant with 'culture' tastes too much like 'pop'