Actually, the stamp doesn't serve the purpose of a visa in a legal sense--it's more like the temporary "hall pass" you got from the teacher or monitor in grade school that allowed you to go to the bathroom. The default position is to use the Chinese terminology (or closest translation thereof).

I don't understand why there is such a devotion to propagating inaccuracies or misconceptions. Is it that hard (for an English speaker) to get it right?
If you need simple terminology, just call it a "transit stamp" or "TWOV stamp." When you call something a visa but it isn't, you DO run the risk of confusing people. Did it occur to anybody here that there is a subset (small but still exists) of travelers that can't do TWOV but actually DO need a transit (or regular) visa? That's why it's important to distinguish. It's arrogant to assume that everybody reading this open Flyertalk resource has the rights and privileges that a First World passport holder casually takes for granted.

Rant over.