If we are up against someone whose an obstacle to another enemy just because of emotional/familial reasons, I'd hope that the character is at least honest about it and at least doesn't do it at the detriment of hundreds/thousands of lives.
I say this because having a character act in a way that's clearly stupid/wrong on multiple levels simply for personal reasons undercuts whatever sympathy that we're supposed to have for that character.
Here's a few major examples from past games to best illustrate my point:
Isolde in Redcliffe is single-handedly responsible for the deaths of hundreds of villagers and the potential deaths of her husband and son because she didn't want to tell her husband that Connor was a mage or specifically that her family has a history of birthing magic-inclined individuals. True, she couldn't have known that Jowan was sent by Loghain to poison Eamon or that Connor would be contacted by a demon to save Eamon's life. But that doesn't change how many lives could have been saved if Isolde had trusted her husband with the truth.
It's supposed to be a situation where a mother is just trying to protect her child. But any sympathy for the situation is starkly undercut by all of the lives lost because of Isolde's stupidity (particularly if Connor himself ends up dying).
Anora's insistence that Loghain be spared of judgement for his actions weakens her bid for queen especially with the evidence and dirt that the Warden can bring out during the Landsmeet. Game Writers have stated that Anora is justified in betraying the Warden to save her father. I'm going to respectfully disagree. But only because she's essentially supporting a status quo that's going to eventually bring Ferelden to ruin and because there is no logical basis after everything that she's seen and learned about Loghain.
Emotionally, it's a little identifiable. But this is the ruler of a country that we're talking about, a ruler who shouldn't let personal feelings and emotional bias interfere with her duty as a ruler. Some will argue that Anora is human and therefore, it's natural to defend family. But all of the other hundreds of thousands of Fereldens are people too with their own families. Is she really willing to put all of them at risk to support her father and yet still believes that she's doing what's best for Ferelden?
This paradox confuses me and it also undercuts any trust or capability that Anora supposedly has which makes any player whose betrayed by her more likely to kick her off her throne and give it Alistair rather he's hardened or not.
Then there was Marethari. Marethari was so determined to stir Merrill away from a path that she believed to be harmful that she kept her clan near hostile territory and even alienated her people from Merrill even though Merrill wasn't doing anything to hurt them. Then she goes to the mountain summit and lets a demon possess her without telling anyone because she wanted to "protect" Merrill.
This situation's pretty idiotic considering the many demons that Merrill has already killed alongside Hawke and even moreso when the clan blames Merrill for Marethari's death and either banishes her or tries to kill her resulting in the death of the entire clan. It also undercuts the supposed danger that Merrill was in because Merrill had worked on repairing the eluvian for years and nothing had happened to her.
The point is if you want to make a character act completely based on personal emotion and still want them to be sympathetic, don't have them take a level in idiot or they'll end up being less sympathetic especially when other people pay with their lives for their idiocy. Being human is not an excuse for being selfish and/or stupid.