"Culture".
I've met more than one people who consider "yell" or "shout" conversations impolite and noisy. There are even forum posts about people asking why yell conversations isn't a thing in FFXI like other MMO, or people ask for functions to turn off yell channel back when it was implemented.
If majority of people shares same opinion about "yell shouldn't be use for chat", then nobody would use yell as conversations tools. And vice versa. Yell conversations became a thing because people's point of view about yell channel changed.
Again, you're trying to make a generalized statement about people's preferences. What if that person just don't care about shout, or PUG? Then that person has no reason to choose Asura.
What happened here is that you clearly prefer a more active yell channel with more PUG/conversation going on, I'm not telling you you're wrong. But what you're doing here on this forum repeatedly, is that you're telling anyone who prefer a quiet server with less shout is wrong. And that's the issue.
Once again, you're trying to apply your own personal preferences on every individual that has different taste, preferences, opinions from you. Surely people are allowed to prefer a 50 people server because he wants all the mandies. While you pop on the forum and scream "HOW DARE YOU PREFER MANDIES OVER PARTIES".
All those characters are played by real people. Of course they behave like real people. What'd you expect? People log on to a FFXI character then suddenly they're not human being anymore?
You have extremely narrow definition about the term culture. Look it up, this came from google.
Culture(n):
"the attitudes and behavior characteristic of a particular social group"
As long as you have a group of people that got together, there's culture. Party to party, LS to LS, server to server, MMO to MMO, classes to classes in schools irl, companies to companies irl. All of these could be defined as social groups and behaves differently depends on groups.