Mob data tag "CustomNameVisible" does not work

When a mob is summoned with a custom name and the CustomNameVisible tag is set to 1 (true), the name is still not always visible.

To replicate:

Enter the command: /summon Villager ~ ~ ~

{CustomName:Dumdum,CustomNameVisible:1}

Look at the Villager up close. It will display its name.
Turn to the side. It will NOT display its name.
Back up and look at it. It will NOT display its name.