Not at all. We were in Bangkok recently and there were plenty of China women 'offing' guys. They and China guys constitute the bulk of the 'offing' customers; hardly any elderly farang to be seen. The China customers (including quite a few Taiwanese) can be quite fun and boisterous and were keeping the beers flowing and the bars afloat.
The afterhours Pattaya karaokes with male hosts primarily cater to Thai working girls looking for hard Thai cock after having had to serve flaccid foreign cock the night before.