I get a kick outta this one...
Just look at the varying opinions expressed in this thread. My opinion? There's generally nothing wrong with chewing gum unless, yes, you are doing so noisily or with demonstrative exuberance. But, again, it's just my opinion--and no better than yours.
When I was an elder, there was a particular guy on the body who simply hated gum chewing. He was an otherwise mild, diplomatic person...but this subject made him rabid. He simply couldn't believe that, at our hall, there was not already a defined policy on this. This is funny, because I now remember how different I was from the rest of the body. Even though I was as zealous as any of them, I commented freely that I thought it wrong for us to set up so many rules about things that asserted our personal opinions--and restricted the personal choices of the friends.
He just shook his head.