These Moors were from Northern Africa and were Muslims. For Shakespeare the fact that Othello was a Muslim was certainly a bigger problem than his color. In our production of Frankenstein several years ago, the director used an African-American actor as the Monster. The reason for this choice was to convey a different set of ideas about the play. Many audience members, however, simply ignored that aspect of the play, and saw it as a evocation of a classic film with and excellent actor as the monster.
Ideas can emerge out of the plot and out of the conversations among the characters.
We'll see all of those next time. One of Cole Porter's silliest musicals is Anything Goes . The play makes fun of the superficiality and stupidity of the American rich in the 1920's. Even plays like The Music Man have ideas. Films express ideas in some unexpected ways.