Take a "Chants": OM with Me!

I've noticed that when I teach in yoga studios, practitioners are all about the OM. They love to chant to open and close the practice. The class's chanting is hearty, vibrant, and somehow always naturally harmonized. It's really lovely and it makes me feel supported as a teacher. It always makes me smile. But when I teach in gyms, I find that practitioners are usually more reticent, self-conscious, and...how shall I say this? Um...extremely "reluctant" to chant OM.

I wonder why? I really want to know! Please let me know your thoughts on this. Do you like to chant? Do you refuse to chant? Why or why not?

Here are my best guesses:

1. It seems kind of weird and out there (what's next? A gong? Incense? Balancing on one pinkie?) and you're just here for a workout
2. It seems vaguely religious and you are opposed to religion in general or worry that it conflicts with your own religious views
   
3. You don't like how your voice sounds
4. You're too embarrassed/self-conscious
5. You don't see the point. Why bother?
6. You don't know what the heck it is and until you have more information, you're just not going there
7. You once suffered grievous chanting injuries as a child and are still dealing with the PTSD after-effects.
8. You recently had your voicebox surgically removed
   
9. You're too busy wondering what the Celtics/Lakers score is
10. Wait...there's chanting?
    

Feel free to respond with a number from the above list or fill in your own. Educate me, people! I'm dying to know!!!