I've trained in gyms all over Texas for about 23 years now (that and I've trained in gyms in different states in the southern part of the US and Hawaii) and in all that time I've only had issues with a maybe 4 guys being obnoxious in what they were doing. I wasn't even directly involved either, just in the vacinity but was annoyed.
Otherwise most people just do their thing and go.
I'm different than most....I smile, I'm courteous, say "please" and "thank you" and "pardon me" and the vast majority of people respond in kind. I let go of the stone cold douche face and attitude LOOOOONG ago.
But if I need to fart, I isolate myself a bit and fart.