> An acceptable compromise would be to enable notifications by default but put a permanent disable option on each and every message so that users could punish a

> An acceptable compromise would be to enable notifications by default but put a permanent disable option on each and every message so that users could punish apps on the first abuse. This is exactly how recent android works (at least, it does on my Nexus 5X). On any notification, you can slide it sideways to access a settings menu where you can immediately block all notifications from that app forever.