Esperanto is super Euro-centric, though, which can alienate people from Asia and other places. Esperanto did have something of a brief boom here in Japan, but the barrier to entry is also high since it shares no vocabulary (outside of some loans into Japanese and Korean, though some of those don't retain the same meaning, and basically very few in Chinese from what I understand), has different grammatical structure, etc. Chinese is basically SOV like many European languages, from what I gather, but Japanese and Korean are generally SVO.
There's also a whole high-context vs. low-context language issue.