I've learned from other server admins, forcing players to change their player name from "Survivor" helps A LOT with looking through logs, especially finding cheaters, stream snipers, pretty much any issue that involves a player.

Why is it not required for a user to enter a player name when joining a server?

The biggest issue with kicking players for the name "Survivor" is teaching them how to change their name.
I haven't been running servers for very long so maybe there an easier way to teach players how to go to Parameters, Player name and check the box.

But if there was a popup before connecting to a server asking to set your player name, this would make things so much better.