I play both and enjoy both. Now, this statement is actually true just to the total amount of players in each. Do the majority of APA 2,3,4 (no offense anyone here who is) know basic etiquette? Probably not (I sure didn't when I was there) but because they likely haven't been around long enough or haven't been shown what's right and wrong in this aspect.
Now, the BCA average skill (around here anyways) is higher than that of the APA. Obviously plenty of skilled and respectful players in the APA, but many aren't that. The majority are lower skill level and not aware of the etiquette. I'm not knocking them as you don't know what you don't know. And, there are guys in the BCA who do the same things. So to characterize one as superior is incorrect, IMO. From my experiences, the actual number of players who show others respect are the same-ish. Just many more APA players so it's easy to lump them all together.
Side note, a very good player who only played APA for years and years joined our BCA team a couple years ago. He was constantly doing sharking things. He didn't know what he was doing was wrong or disrespectful. Most people are happy to learn and once you show them what they're doing is wrong, they are actually very sorry and rather embarrassed.
This is pretty much the conversation I had with myself in my head, I do appreciate this. I wouldn't mind taking a second to teach someone, but how people would actually be receptive to my advice, is another thing entirely.