The people nearby and friend invite requirements being in problem in India but not in China can be explained by:
> QQ messenger – already had over 750 million monthly active users by the time WeChat launched. A user could port her entire QQ social graph to WeChat by just logging in with her QQ ID.
It sounds like WeChat is really just a renamed QQ of sorts. So any adoption comparison of messenging app uptake in other countries with that of WeChat in China should use the QQ launch of 1999, which makes WeChat's rise to ubiquity far less impressive.