The Article states:

"The Native American flute is the name of the instrument, so anybody who picks one up and plays it can call himself a Native American flute player," [Thompson] explained. "It's not so much the fact that they are playing the flute that bothers me. It's the fact that a lot of them are non-Native and try to play the part of a Native, wearing what they think is Indian attire. It's offensive."

Why did the author include this passage?

To provide information regarding the proper dress Native American flutists wear during a performance
To analyze the role of non-Native American musicians in the development of Native American flute playing
To explain why Thompson considers some flute performances by non-Native Americans insulting
To encourage Native American flute performances given by non-Native American musicians at cultural music festivals

The author included this passage to explain why Thompson finds it offensive for non-Native American musicians to try to play the part of a Native American while performing on the Native American flute. It highlights the issue of cultural appropriation and insensitivity.