If you want to know exactly why you have to have two Facebook apps to do what one Facebook app could do before, well, Mark Zuckerberg is here to tell you. Kind of.
Speaking on a live Facebook Q&A, Zuckerberg fielded a question about his decision to unbundle the main Facebook app and split Messenger off to a separate, standalone app.
Apparently, the old Facebook app with chat functionality simply had too much friction.
Here's what he had to say (via The Verge):
We wanted to do this because we believe that this is a better experience. Messaging is becoming increasingly important. On mobile, each app can only focus on doing one thing well, we think.
The primary purpose of the Facebook app is News Feed. Messaging was this behavior people were doing more and more. 10 billion messages are sent per day, but in order to get to it you had to wait for the app to load and go to a separate tab. We saw that the top messaging apps people were using were their own app. These apps that are fast and just focused on messaging. You're probably messaging people 15 times per day. Having to go into an app and take a bunch of steps to get to messaging is a lot of friction.
Messenger is its own app now because tapping your Facebook app and then tapping one more tab to access chat was very, very hard, apparently.
And on why the shift was forced on users so abruptly:
Asking folks to install another app is a short term painful thing, but if we wanted to focus on serving this [use case] well, we had to build a dedicated and focused experience. We build for the whole community. Why wouldn't we let people choose to install the app on their own at their own pace? The reason is that what we're trying to do is build a service that's good for everyone. Because Messenger is faster and more focused, if you're using it, you respond to messages faster, we've found. If your friends are slower to respond, we might not have been able to meet up.
That clears everything up, right?