Thought it was the Mainland Chinese, but Hong Kongers are equally loud??

Am in Japan.

All these while I had assumed that it was the Mainland Chinese that are really loud in foreign places. However, today I was told that those peeps were actually Hong Kongers speaking canto with a mix of very accented English.

Why are Hong Kongers also so loud? I had thought that there would be more civic mindedness.

Edit: I am in Shinjuku, train is quiet, bunch of HK just walked in and talk like they own the world, suddenly it's like I am in Kowloon. It's so inconsiderate to the host country. 😭