I understand that but after seeing the discussion about Merrill I thought that it's also important that the character is clearly demisexual. Or have I misunderstood something? I haven't read all the posts.
I'm going by a summation here, and I apologize in advance if I screw up some of the details. Hana (or whomever,) please correct me if I'm mistaken. I hope I say this right. 
From what I've gathered, the issue is that Merrill was stated as bisexual. Most bisexuals tend to fall into the majority of the population when it comes to a sex drive. Some folks, including Hana, felt like they had found a connection with Merrill in terms of sexual identity prior to this reveal. I know that Hana for instance identifies as demisexual.
Merrill, unlike most of the female LIs in Dragon Age prior to that point, never talks about sex prior to the romance "lock" scene. Given her nature as both a Dalish outcast and her stated treatment by her clan even before the blood magic came into play, it's easy to assume that she had never found anyone special enough to really feel a sex drive. She makes remarks on shirtless Qunari, but at least for me, it struck me more as admiration than anything sexual. Ace/demisexuals can find people appealing to look at, but don't get turned on by it in a causal manner. Unlike Fenris, who isn't dissimilar in that respect, she doesn't start a relationship with another party member if left unromanced.
When David Gaider said that all of the LIs were bisexual, including Merrill, this was a disappointment for some players. Asexuality and the sexual identities associated with it, are rarely talked about in terms of romance in media in general. Merrill seemed like the perfect fit, and to have that taken away stung for some people.
Now, to be fair, I think it was a matter of not knowing what demisexuality was at the time. Which was understandable, since I didn't even know about it until just over a year ago. DG knew that Merrill wasn't asexual, and that she was interested in both genders. Try saying, bi-romantic demisexual elven romance three times fast. 
So, this thread is around in the hopes that the devs read it and at least take it into consideration. They'll do as the wish for the characters, but for me, trying something like this sounds awesome coming from this company. Sometimes, it's not about what a character states that's important to people. Sometimes, it's just in what they do.
I'm not demisexual, so I'm not an expert. This is just what I've seen since this thread was created and there's a chance I'm not saying certain things correct. However, I'm happy to see that ace/demisexuals on the forums have a place to hang out and talk to each other while giving some cool character ideas we can all enjoy.
Edit: Wow, had to fix a very bad sentence. So sorry about that!