I think I'm with @Granath here, for all the reasons mentioned. The Mordin mission in ME2 was masterful, get up and walk away from the computer for 20 minutes to think it over. And it works so we'll because it is the result of pained decisions made by individuals that you can see clearly grappled with the difficulty. Mordin is not solely convinced of the righteousness of his actions, and his doubt builds upon the world and his character. It is a decision where you can see the weight on the world, how it informs many other decisions in plausible ways.
It's so good because it takes the background of the universe and plays it out in front of you, and ask you to judge 'did we do the right thing'. It isn't something tangential to the world, but integral. It is Bioware at its best.
It was clearly also not written by the same person who did the reaper baby.