How you learnt you primal/coil fight?

[Artiste]

But go blind and go careless are two distinct things. If I learn that killing the turtle is bad, I will never kill the turtle again. When someone headlessly will continue to kill that ***** turtle, here we have a problem

The problem is that, some ppl cant read, it's ok to not know how to do, but I already saw a tank dpsing the turtle for a while, I was saying him to stop, and, it's a good thing that he wasn't dodging, I just let him die, and it worked.
Now, I'm wondering if he was not simply a bot, someone cant be that stupid... Seeing that he's dying and still not dodging... why ?

For me, I learned at begining with videos, already was cleared when I came.
For Second coil after, learned with guide, when they came (there is always group that clear faster that write guides)

And for the " news primals ":
Leviathan : Went 3-4 times in HM, went in Ex after, cleared fast coz this one is too easy
Moggle : Just watch a video once, not too many things to know, just some dispel to do and things to dodge at middle (If you stay there, I prefered staying there to be in range to heal everyone)
Ramuh : Yolo, learning with my team, didn't saw any guide before we cleared (maybe there was one, didn't search), it's not a fight hard to understand, but it's sill not simple.