Final answer:
Woody Guthrie was frustrated that his song became known for its melody and harmony instead of its original protest message, which is part of a broader issue of art losing its critical edge when it becomes popularized.
Step-by-step explanation:
In his last years, Woody Guthrie expressed frustration that his song had become widely known and popular, but without its original protest message and socio-political context. Guthrie's concerns likely stem from his song 'This Land Is Your Land' becoming a folk anthem, often performed without its critical verses that challenge private property and economic inequality. The omission of these verses leads to the song being celebrated more for its melody and harmony rather than the radical message Guthrie intended.
While the question specifically targets finding the missing word from the provided options, Guthrie's frustration was related to the larger issue of his music being embraced in a manner that stripped away its critical edge. The popularization of the song in a way that focused on its lyrics while placing less emphasis on the political message could be seen as a detachment from the original intent, reflecting a broader trend in how art can be sanitized or co-opted over time.