Why do people think that cracking their knuckles all the time is acceptable?

I’m not saying when it happened accidentally, but the forced “click every finger on both hands” thing. They say if they don’t do it multiple times in one hour that “the pressure builds up and they feel uncomfortable”. I want to say… guess what, I feel sick to my stomach from the sound of it and it gives me rage. It is compulsive behaviour resulting in an unpleasant noise they impose on others and I can’t stand it. Farting in public is not acceptable even though NOT farting can result in bloating and uncomfortable feelings. Same with burping. We fart and burp in private so why is it ok to do the “clicking”? P.S. we’ve had family around and during a movie one of them did it every 5 min. I worked so hard to force myself not to say anything.