Unlike you, I can make the comparison as I've been a licenced secondary school subject teacher back home.

While the UK may be a hardship location for you, and it is your full right not to return there, it is easy in China as you are fully retired. For a younger FT with no pension/savings in China, I think that is the age bracket SB is referring to, or an older bloke with no savings/family/friends/back home.

He is not referring to you personally or guys of your age who are retired in China, and/or who were real qualified subject teachers back in the UK. As you rightly state, you can make that comparison...but there are those older blokes who cannot, and for them China can be a life of nerve wracking worry on a knife edge, the Chinese could kick them out at any time, and they would be old, unemployable and alone in Thailand or somewhere, not sure if that could be better or worse than being on the social in England, probably worse, as no benefits would be paid to foreigners in SE asian countries. Good thread this one.