I really don't get this idea that Dorian's orientation was somehow 'forced.' I mean, people have sexual orientations in real life, and Bioware games have always reflected that (except DA2, arguably). Dorian is perhaps unique in that his sexuality plays a big part in his back-story and personal quest, but again I don't see how that makes it 'forced.' Sadly, social rejection due to orientation (particularly by parents) is still something that a lot of LGBT people have to endure, and so it makes sense for the writers to incorporate that into one of their characters. I suppose you could say its a little odd that homophobia seems to exist in Thedas only now (it clearly didn't before), but even that is explained by the fact that Dorian is from a different cultural background (Tevinter) which we haven't really seen first-hand anymore.
And its not like Dorian lacks for personality other than his homosexuality: he's excellently written and has a lot of interesting views on Tevinter culture, magic e.t.c.
For people criticising this portrayal, it seems like they are only willing to have LGBT characters when the portrayal of their sexuality is so tepid that it can easily be ignored. But in reality, sexuality is a massive part of some people's identity, and it seems odd to suggest that Bioware shouldn't recognise and deal with that.