Passwordless automount under regular user

Good Morning dear Debian GNU/Linux users!
I've got a question for you: What's the reason I need to create following
automount rule for polkit
in order to mount disk partitions without a password from any GUI
filemanager?

[Allow Unauthorized mounting/Unmounting]
Identity=unix-group:plugdev;cdrom
Action=org.freedesktop.udisks2.filesystem-*;org.freedesktop.udisks2.eject*
ResultAny=yes
ResultInactive=yes
ResultActive=yes

 Is this intended behaviour and what is the case for doing this?

  Why don't  maintainers set this up by default in Debian?

  Ubuntu and its derivatives have the feature has been enabled.

 So, would you like to explain the matters to me?