What is all of this about? Simply, cultural appropriation.
What is that you ask? When one group takes the traditions, views, trappings, or other elements of another group to use as their own. Often this is done with little or no regard to the deep meanings and cultural significance of those elements to the originating group. There are many layers to cultural appropriation, and much of it comes down to power dynamics. Often racism plays a part as well. Sometimes it all comes down to ignorance; sometimes innocent ignorance, sometimes uncaring ignorance.
For example, Katy Perry recently came in for a healthy dose of criticism for an image in her video for "Dark Horse." In it Perry, in the guise of a pharaonic goddess/sorceress, incinerates a line of suitors, one of whom was wearing a pendant which said "Allah." Well, needless to say, a pop star setting fire to the name of God could be viewed as insensitive. Perry had the image of the necklace scrubbed from the video and offered an apology saying she was simply trying to pay homage to a culture she loved.
I would call that innocent, but ignorant cultural appropriation. She was going for an "Egyptiany" feel and didn't pay much attention to the fact that the cool squiggly Arabic script on the actor's necklace might actually have significant religious meaning to people (belonging to one of the world's largest religions). Oops, her bad.
On the other end of the spectrum is the fashion industry which has been plundering Native American cultures with impunity for some time. Whether it was Victoria's Secret slapping war bonnets on underwear models or Urban Outfitters launching an entire "Navajo" line of clothes (and refusing to apologize or pull the products when the company was sued by actual Navajo people), that kind of intentional misuse of a culture's imagery is not so innocent.
Where on the spectrum does that leave bellydance? Depends on who you ask. Ms. Jarrar has made her position fairly clear; if you aren't of Arab descent, you shouldn't do it. And she has a point, under all of her vitriol. Slinging on some eye-liner and a jingle-scarf can't make you a bellydancer. Bellydance has a long history and deep roots in Arab (and North African, and Asian, and Middle Eastern) cultures. But here's the rub, for me. While bellydance is rooted in all these various cultures, what we know as modern bellydance is not derived from one individual culture. Dancers have been sharing and copying movements and costume styles from each other's cultures all along.
The term "danse du ventre" (dance of the belly) was applied to Egyptian dancers by Napoleon's troops. In the West, the term came to be applied to all such Middle Eastern folk dances. The dancers who were performing these dances were doing so as a form of public entertainment. As entertainers, they were ready to incorporate anything that enhanced their performance, whether it was culturally questionable costuming or movements from another part of the world. When we talk about bellydance today, we must be clear about what we are talking about; private expression or public entertainment. The dances Arab women do together in their living rooms and at parties is not what the sequined dancer at the local Moroccan restaurant is doing. Even Ms. Jarrar makes a distinction between the dances women do together for fun and the professional dancer hired for the wedding reception.
Clearly I have my own bias. I am a white bellydancer. I teach and perform with African-American bellydancers, but I am pretty sure Ms. Jarrar would include them with the dancers she can't stand (how do the dancers who are Black, or Hispanic, or Asian feel about being classed as White in that article I wonder?) By Ms. Jarrar's standards I suppose the only form of dance I could practice would be Irish step-dancing, or maybe a Polka. But I am a white bellydancer. I understand if Ms. Jarrar doesn't want to tip me because I am not Arab (I once met a man who didn't want a black mechanic to work on his Saab--sounds pretty bad when you put it that way, doesn't it?). Thankfully not everyone feels the way she does.