He doesn't push the male PC out of the way as he does with a romanced female PC.
Well, I think you're conflating "romanced PC" with "female PC." Had Alistair been open to romancing a male PC, I'd not be surprised if he did the same thing. I don't think the scene you describe
must be a reflection of choice of sex, simply because it happened to be one. Sort of an idea of a correlated variable, but ultimately a different cause.
This may not be the place for it, but while I'm here, I may as well ask how you feel about the idea of a non-PC's personality. I am sorry for being a broken record, but back in BG 2 there were a number of criteria that would stop a PC from initiating a certain romance - typically this was related to race (and, I suppose, sexual orientation).
When I first experienced the romances during testing, I actually met with some resistance. I also felt that, on some level, that the character was less consistent took "something" away from the character, though I couldn't quite put my finger on what it was.
It wasn't really a deal breaker, and upon coming to the conclusion I realized it was only inconsistent outside of the game world, and hence meta, ultimately it stopped bothering me.
While the ability to change races has been removed from Dragon Age for now (to my knowledge), would it be problematic for a character like Fenris to have been unable to romance a Mage Hawke? Fenris clearly has hangups over mages, somewhat akin to the tensions between drow and elves. Or, back in Dragon Age Origins, for Alistar to not really be attracted to dwarves (I was going with Elves, but considering Maric's habits...)?
The thing about Fenris, is that his character has some sort of motivation for not liking mages. I can agree with the notion that it's perhaps a bit silly for Fenris to hook up with a mage (I don't know how the story goes, because at the same time I think people like challenging a character's prejudices and stereotypes).
I'm not against the idea of having Fenris cut off from mages. The thing is, as I've learned on these boards, is that for some the romances are
very very very very very important to them. Going as far back as Baldur's Gate 2, there was disappointment regarding the balance of romances (not even considering a gay romance) between men and women. I know people modded the game to allow for these romances to be more available. So, on some level, there's the idea of having some sort of balance.
Coming back from that tangent, however, I think people might be more willing to accept if Fenris' depiction had been much more anti-mage, given what they learn about Fenris in the game. My question for you, however, is: is there anything in the game that actually makes it logically inconsistent with the game world as you know it, for Fenris to be in a relationship with a man? How about a woman?
I can fully understand and agree that it's reasonable for Fenris to reject a mage. Of what importance is it, that Fenris reject a man or a woman? To me, it seems like the principal reason is external of the game. Am I wrong?