Morrigan in DAO is different from the one you see in Inquisition
even if she is in a non friendship and romance she will offer to you the ritual, even if you betray her at the circle tower (morrigan restoration patch), for her the soul of the beauty god is more important than the life of a warden (especially Loghain) during the night of Redclieffe.
There is no grey in her behaviour in origins just darkness ( the elven slaves, the girl of yonelath, the dwarf of orzammar and the anvil, the people of redclieffe, andraste's ashes ecc).
Sten is grey(he kill an entire family but now he want to hel ferelden and restore his honor), leiana is grey(she is an assassin but she now want to help you for nothing in return), zevran is grey ( he is an assassin but he care about the elven slaves), ( brother Burkel and wynne are the only Saints in this game)
And this is the reason of my question maybe she can become less pragmatic after DAO.
Just I said before, you'll never understand her upbringing. The Warden is the only person she loved or befriended and she doesn't want to see him/her to die and that's why she is proposing the DR with Loghain or Alistair even if you deny it if male.I think you never question her life in the Wilds and easily jump to conclusion that she is evil. You are very black and white.