As it is right now all it does is make everything gray just like it would in standard, which is obviously quite silly as you'll have no clue of what to hit.
Even though this could be used similarly as spunout (for unranked play), it would be multiplayer exclusive which at least I find to pretty much justify it.
You got the choice of playing after missing in standard, zero reason to make the map completely unplayable just because it's taiko.
How to replicate:
1. Play Taiko with Sudden Death mod
2. Miss a note
3. Grey notes everywhere, preventing the player from telling the difference between red and blue notes.
Even though this could be used similarly as spunout (for unranked play), it would be multiplayer exclusive which at least I find to pretty much justify it.
You got the choice of playing after missing in standard, zero reason to make the map completely unplayable just because it's taiko.
How to replicate:
1. Play Taiko with Sudden Death mod
2. Miss a note
3. Grey notes everywhere, preventing the player from telling the difference between red and blue notes.