I'm not sure which forum this thread best fits on, as it is partly Open Debate, partly Wuxia, partly TVB, and partly Music, so let me just put it here on the Wuxia Forum.
TVB's first Jin Yong adaptation was BOOK & SWORD: GRATITUDE & REVENGE in 1976, starring Adam Cheng, Liza Wang, Gigi Wong, Lee See Kei, and others. It's remembered as a TVB classic.
As always during those days, TVB commissioned composer Joseph Koo and lyricist Jim Wong to write the theme song of the series. The song, recorded in two versions (one by Adam Cheng and the other by the late Roman Tam), featured lyrics that are roughly translated into English thus:
The heroes of the Red Flower Society's
Crimson blood colors ten thousand years.
Restoring our Han rivers and mountains.
Vowing to destroy the Manchurian barbarians.
That fourth stanza of the first verse is the problematic one. It expresses a desire to wipe out an entire race...genocide.
That's honestly probably how the characters of the Red Flower Society actually felt towards the Manchurians. They hated these foreign invaders who had conquered their homeland and enslaved their people. This theme would be revisited in LOCH with Gwok Jing and the Juchen, in HSDS with the Chinese wulin and the Mongols, and in DGSD with the Chinese wulin and the Khitan.
There was a certain amount of racism in the storylines among the characters, and the song lyrics merely reflect that. Even so, isn't that one line, although accurate to the themes of Jin Yong's novel, a bit extreme? Imagine a popular TV series or movie today with a theme song that sang about wiping out all Japanese or all Russians or all Muslims, or whatever. There would be (rightfully) an uproar.
TVB's adaptations are popular in many places in Asia, including Manchuria. Imagine being a Manchurian person watching the TV series and hearing the theme song with a lyric glorifying the act of wiping out YOUR people. Would you still sing along?
This song is definitely not very P.C.