Brought up more as an example that heterosexual relationships typically aren't seen with the same scrutiny due to being more prevalent and familiar.
I do think Aveline's plot arc would have been received differently had Donnic been a woman (or Aveline a man), based purely on the same sex relationship aspect. It might be an "agree to disagree" part since I think that if only that was changed, people (maybe not you) would still frame the encounter as being "forced" as a result of it being a gay relationship.
I agree that it likely would, same as how some people find Dorian's mission cliche because gay and daddy issues was brought up. I don't agree that was cliche, and I wouldn't agree aveline's thing was forced if it was a woman either. People confuse something that is forced with something that makes them uncomfortable or that obviously breaks the norm of what they're used to in an obvious way. It's not the same, as you already know.
But anyway, people give Krem more scrutiny partly because yes, this certainly is something very new to the gaming world, but mainly it's the way it was handled. The one saving grace it has is that you do not have to ask Krem about Krem's gender identity, I believe. only if you ask about it does it get brought up, so because of that, I don't know that I can say it was forced on that alone, though it did feel preachy.
However, what makes it feel forced for me, is that it seems to go against what Sten tells the player in Dragon Age Origins:
Now, I am aware Sten has some other dialogue that makes this a little confusing. On one hand he makes it seem like a woman cannot be a man, but the argument presented is that of course a trans man person is not a woman to begin with because that is not what they identify with.
That's all well and good in our society, but does that honestly seem like something the Qunari would adopt of all people? I am not so sure about that, and neither are a lot of people, gay straight, trans, not trans, etc.