I have no qualms using WhatsApp. It is a very efficient and useful app. They should probably merge messenger and WhatsApp (or maybe not lest they end up making WhatsApp bad too)
I hope the bigwigs at FB don't read your comment. Messenger and whatsapp should never be merged. Part of the reason why I'm glad that Messenger is doing so well (I don't use it myself) it's because I believe that gives them less incentive to mess with whatsapp too much. It's very likely that they will fuck it up eventually but the longer it stays usable the better.
from what I understand, WhatsApp works in China and Messenger doesn't. So I doubt they'll merge. But it'd be nice if you could message from one to another
