Why do some people (Lucas included) think Mos Isley should be a big, busy, sprawling city? The OOT depicts it as a run down truck stop. Much like those you see on the highway in the middle of nowhere. Not too busy, but necessary. I like that much more.
I have no idea. Most big cities aren’t wretched hives of scum and villainy either. Usually big cities have specific parts that are bad, and others that are good. It’s really only run-down places that are entirely wretched.