People like this would without a doubt be unemployable in the UK, even for a menial job like working as a cleaner or something like that. Backbitting, gossiping, these are all behaviours which while acceptable as a part of chinese culture would quickly lead to disapproval from your work colleagues or even dismissal.

That's true. And Chinese employers are good at choosing the potential gw's from among their job applicants based upon the information and tone of individual resumes!
Too many foreigners who work in China eventually adopt the rotten work culture that is prevalent here! Disgraceful indeed!