You said what I was going to say- the proportion of foreign to American tourists has been increasing steadily for at least 25 years at Disneyworld- high ticket prices also deter the riffraff, including me.
Busch Gardens seems to be able to keep a clean, well mannered park. I’d recommend them. Six Flags crowd can get a little rough at time, but they have lots of rides. If you really want a rough crowd, check out Dallas High School night at the State Fair. Cops have to walk a fine line between preventing a riot and causing one. Got caught on the wrong side of the mounted police line one year.