I don't have FB Messenger on my phone because, like most apps, it wanted access to things it didn't need to have and I didn't want to give. There's no reason for Messenger to need access to ALL of my phone contacts when half of them weren't even my FB friends. To Message people on FB, you only need people I have on FB- not everyone I know. So screw that; if it's that important- and it never is- it can wait until I get home.
Now there's another reason not to have FB Messenger. Facebook Dumps Intern After He Pointed Out Messenger's Creepy Location Tracking
Mark Zuckerberg knows if you're at Starbucks... he knows if you're at the movies...
This really shouldn't come as any kind of surprise given Facebook's track record with privacy and data mining. I'm not telling you to stop using Messenger, but as always- User Beware. And protect yourselves.
Let's be careful out there.