In my opinion, there is no need of a "boss enrage" in normal mode.
However, even in normal mode, healers aren't supposed to be able to raise over, and over, and over, and over...
Right now (but it's not news), the almost infinite ressources of healers and tanks are absurd.

Of course, by essence, DPS players are supposed to fight against a "time's up", but this countdown doesn't have to always be in the boss pattern, like FFXIV does.
The countdown is also supposed to be their teammates' ressources (healers' MP if you prefer).

The balance of FFXIV battle system is severly out of order for a very long time now.
The trinity tank-heal-dps is completely broken...