Why do Hong Kong chefs use a white towel instead of gloves to clutch a wok?
Because it is more efficient when running the kitchen while in full service.

It takes less time to remove their hands from the towels than it would take to remove gloves.

This also applies to chefs in other kind of cuisines; if you look at french cooks, they will do the same thing; grab a towel to pick something from the oven, or pick a pan from the stove.