So i took a look over at the Steam threads.

[graykin]

The concept of the achievement, however, goes against the main principle of Frictional Games. They have stated in the past that the motivating factor behind making their games was to provide a unique form of storytelling, while at the same time providing a horror-filled atmosphere and enjoyable, flowing gameplay. They have argued against making games that are solely about competing against others, or being in any way "meta-gamey."

To add achievements would undermine the entire purpose of Amnesia.