Plain and simple; she has no right to be disrespectful; this is clearly written in law and practiced in the courts. For those who lived through the Flag Burning fad, I am sure that you remember the coverage; flags may be burned, but only in a respectful manner. To me, this latest "fad" is inclusive in those decisions; if someone doesn't want to stand respectfully for the anthem, don't be on the field/in the arena, but you may not be disrespectful.
As for the "protest", it is nothing but sheer nonsense. Protest where and when it is appropriate. IMO this whole thing is nothing more than a publicity stunt by an inconsequential backup player trying to get on Sportscenter.
For Ms. Rapinoe, as part of the USWNT, she is representing the USA. From that standpoint, it is my feeling that she should be removed from the team, as being disrespectful to the symbol of our country is antithetical to her being a member of the team. The coach of the Men's Hockey team got it right; you sit for the anthem, you sit for the game.
Recall a few years ago when a player from (one of the mid-Atlantic state "blue" schools if I remember correctly, but I can't remember which) decided that she would protest the war in Iraq by turning her back to the flag during the anthem. When Geno was asked about it, he made it clear that players represent their University, and therefore must display behaviors that the University embraces. He went on to say that the University of Connecticut doesn't support this type of action, therefore no player wearing a UConn uniform would do so. The connotation was loud and clear.