The chanting itself isn't that big of a deal to me. Sure, I'd *rather* hear the ambient sounds and music piped into each land, but a little chanting from anyone is fine as long as it's outside and passes by relatively quickly. If, however, I'm surrounded by it, outside or (especially) in a closed area such as a bus or inside queue, then it's a matter of courtesy. You can say it's a cultural thing, but if that's the case, then why is that culture so discourteous?
What I'd prefer Disney to do something about is individuals (using from the same demographic that are known for chanting) who hop railings to cut in line in front of people or who bump into each other rudely to get from one place to another. I had both of these happen in January in the queue for Buzz and the CM who saw it happen just shrugged her shoulders.