I think the problem is that Sera is the only one with a persistant option to kick out at any time while with the others you can only kick them out at certain points. I'm one of those people that don't like Blackwall and didn't even before I found out his twist. If I have the option to kick out Sera at any moment why can't I have the same option with Blackwall?
I'm realist enough to know I'm unlikely to see a lesbian leading lady any time soon but I'd still like to see a lesbian/bi character be more developed and have more significance to part of the main plot even if they're not going to get Cass, Alistair, Morrigan level development and significance.
I sorta find it strange that none of the DA2 relationships seem to count and neither does Liara from ME. Am I mistaken?
I felt that the reasoning for allowing Sera to get booted is due out of all the characters, she'll probably be the most antagonistic. She is arguably one of thee most amoral characters of the bunch. There seems to be general consensus on these forums, that is only a guess from looking at the total number of pages on the "lets hate sera" thread, which I may or may not have commented on... I plead the fifth.
At any rate, it appears Bioware was aware of this and provided a way out. I just don't have a bone to pick I guess because I'm not even remotely invested in anything to do with the character. I suppose if the only heterosexual was a complete buffoon who rubbed everyone wrong and Bioware offered an immediate "get the hell off my lawn" option that would be deeply unsettling, more so do to my privileged upbringing and being unable to imagine living in a world where being straight is demonized. I literally can't picture it and I imagine that if it were me on the receiving end it would turn me into a hateful little troll... not something I'm proud of, but honest about at any rate.
I don't find the idea of a lesbian or bi lead character all that strange, especially if a female character. I think in the minds of most it was already achieved with Liara who had a major roll in 2 of the 3 ME titles. What is one more LGBT lead at this point? It's very difficult for me to see an issue because I'm not the one being offended. I feel that due to bi options even being available to begin with somehow satisfies straight, gay and lesbian in a way. Just not in a quality fashion. I had to settle for such in DA2 and although I thought those relationship were complete S***, I was never feeling that I got slighted because there was no straight relationships to be had.