Earlier quoted context omitted.
I call shenanigans for two reasons: 1) you can never assume a recipient ever has their phone on, with them and in a non-silent mode 2) users can disable push notifications for individual apps anyway
For some reason I feel like I have become some sort of FB defender, but I am not. Just to be clear, I am not a fan of FB. I even completely got rid of my FB account a year ago because I got sick of fake interactions on the site and have never looked back. I am happy with communicating with close people just via text and other special purpose communication apps. That said, the reasons you mention are pretty edge cases…
Also, if they're supporting desktop clients I again call shenanigans on your argument.