Didn't BW make all the companions bi to satisfy the base whims of the gay community ?
OR Bioware wrote all bisexual companions to keep them all available to their straight fanbase. 
'Forcing' people to engage in a LGB romance to experience content still seems a lot more (generally) taboo then asking LGB gamers to play straight...even if that is arguably more messed up.
anyways....
I'm trying not to let the way ME3 handled things dictate my feelings on this but its difficult. I know many people thought Traynor was cute and all, but personally, she was lacking. And the general treatment of Sam and Steve in that game just really felt like they were lesser characters then the companions. So, while I AM excited by the idea of seeing gay/lesbian companion characters for the first time, I'm very nervous about how the content will be handled (especially since there will be NPC romances it seems-if Scribbles is female only I will be suuuper skeptical is all I'm saying)
Regardless of who ANYONE chooses to romance, we will have 2 LGB companions (maybe more depending on if the NPC's are both bisexual), and no one will be able to say 'such and such wasn't gay in my playthrough' and have a leg to stand on. This is nice and important in its own respect even if it is potentially disappointing in terms of LI options on any given playthrough.
I would also love if one of the non romanceable companions let us know they were LGB (and then ya know, gay people populated the world). If people are upset about the 'realism' of the all bisexual LI approach it would be nice to see more open support for stuff like this (and not just a quick comment in response to it being brought up, actively bringing it up and supporting it on ones own).
But that was a badly written announcement, and a disappointing way for all this news to officially come out.
Also... this feels like it created this weird/awful mentality of some people trying/hoping to shove the romantic partners they don't like off onto other sexualities(Keep him, take her, I don't want that one)....which is just...uncomfortable...