This is ridiculous in my opinion. No, they definitely shouldn't be banned.
Put yourself in their shoes for a minute. If a horn was a popular footballing instrument in this country, and visitors to our country came over and started complaining to the point where the FA considered banning it from matches, there would be an uproar.
I honestly believe that people are complaining for the sake of it, and conforming to what seems to be the majority's attitude towards these instruments. I would even wager that, once you begin to focus on the football in front of you, you drown out the noise to the point where you barely notice it. Deny it all you want, but I've watched every single game so far and it hasn't affected me at all past slight annoyance early on.
The only real argument one has in regard to banning them is if they are interfering with team communication during matches, but even then, both teams are facing the same issue, and should find a way to deal with it effectively.
So no, they shouldn't be banned, and nor should anything just because some visitors to a country don't like it.