Our decisions do matter- you're the one saying Bioware can't tell the parts of the story they want to tell.
They give us a lot of room to customize, but sometimes it's easy to forget that it is their story we play, That, for all the freedom we get over choices, there is still the limitation of being within their story. It's a trade off that every gamer learns to deal with. If one doesn't like it, then they probably shouldn't buy the games nor be on the official forums.
Besides, I thought that's why a lot of gamers like BioWare games. To see the branching paths of BioWare's story, and giving us the choice to tailor our experiences. If one wants to create the ultimate game were every single little choice mattered, and every single play-through that's different, and the player gets every little thing they want, then go for it. That would take a very large budget to do, and one would find that it isn't as easy as it sounds.
Even the most "open-world" games, like Skyrim, are going to have boundaries and limitations that are inherent to the story.
Rather than worry about that, or worry about a companion I couldn't romance from over 2 years ago, I'd rather wonder if Solas is going to treat Sera like a younger sister, or find her too hectic. I also wonder if the gay romances are race gated. DG did say that not all of them were, and I think it would be a poor idea to make, say, Sera locked out for any Qunari and dwarf lesbian PC or Dorian (if my theory works out and he is gay) to be locked out of other races as well. Especially if those are the representations for gay and lesbian players.