Armor Stands are not invisible in spectator mode

Armor stands have the ability to be set to invisible. This invisibility works in all gamemodes apart from one. In SPECTATOR mode the player will see aprox 50% opacity version of the armor stand, despite it having the invisibility tag set to true.

Steps to reproduce;
1) Spawn armor stand that has invisibility enabled
2) switch to SPECTATOR mode
3) observe that it is not invisible

Reasons why this is a really dumb design choice:

• Holograms are basically impossible to use practically along with spectator mode
• There is no logical reason why a player in spectator mode should need to see invisible armor stands because they are used in many "behind the scenes" areas of adventure/custom maps.

If this isn't fixed then Spectator mode becomes a large enough inconvenience to prevent its use, especially on servers or other vanilla custom game modes that utilize holograms or other floating items with armor stands.