Not being the PC one in this thread, but not being one against SGR either, the more I play, the more I think this should be made an option, just so people have a choice.
My SI has 1 option. My BH has 1 option. Don't even get multiple options with Talos or Gault (love his personality, but I really couldn't see my BH going after him).
And it's not a case for all classes/genders to have just 1 option. I just happened to have two of the characters I've focused on stuck with 1 option
Edit: And thinking about it, that's like the "Time and budget" reason. Some of the scenes wouldn't work if you, so they'd have to make new scenes/triggers for scenes.