But all the things they said they couldn't relate to about the Dalish Warden are things that can be decided by the player.
Tamlen's fate and Merrill's obsession with the Eluvian can't be chosen by the player though. If you are playing as a male and don't have that ship-tease, or simply don't care much about Tamlen (he's well-meaning, but kinda arrogant) then his fate won't resonate with you at all?
Same with Merrill, if you didn't much care for her character in DA2 or the Dalish Warden, then it's harder to be invested in some of her plotline, since it's so heavily tied to those events (since they happened regardless of whether Mahariel was the Warden).
Not to mention, once again, the Dalish plot thread in DA2 about the mirror goes nowhere because she never fixes it at all. Adding insult to injury, the whole thing is even more of a Shaggy Dog Story in Inquisition now we know that she could never have fixed the mirror anyway without a key. Unless she found one between DA2 and Inquisition, once again, that plotline feels like kinda a dud, since it has little bearing to the game it's in.
Aside from a few remarks here and there, as well as during the Nature of the Beast, Mahariel's status as a Dalish Elf barely means anything in Origins?
(Dwarves have the same issue, ever wonder why only 5% of all players pick them in Origins according to the stats?)