Why was Judy always treated like she was so homely and awkward?

Judy Garland, who was attractive as well as being supremely talented, seemed to always get slighted by the producers and writers at MGM. This is the second film in a row I've seen (after "Love Finds Andy Hardy") where specific reference is made to her lack of "glamour" and she is basically treated as an ugly duckling. While she's not as dolled-up as June Preisser in this, there's certainly nothing wrong with her! In retrospect, it all seems rather cruel. But then, there's a lot in this film that is a tad bizarre now, like the finale, "God's Country" (lyrics along the line of "They have the fuehrer, we have Shearer"?) and the title tune, done to a rampage through the streets ending with a bonfire was a bit jarring in tone for a musical comedy. Not to mention a bunch of pre-schoolers providing the orchestration to "Where or When" and sounding like nothing so much as...the MGM studio orchestra!