If this was a populated hostile map then it would have been Colorado MKII(and nobody would have wanted that).Creating a barely populated hostile map was a better decision imo because it makes infiltration much more fun and it also fits better the sad atmosphere of this level.
Could you explain this a bit more?
That’s true,but it is just one mission story so what did you expect? 
It still has 3 outcomes in terms of kill methods(pushing Alexa over the balcony,making Alexa commit suicide,making Emma poison Alexa) and the 3 outcomes in terms of dialogue(blaming Emma,blaming the butler,blaming Zachary).
I personally don’t think so…
→ The many pipes,ladders,open windows and secret passages make the infiltration unique.
→ The family meeting changes the routes of NPCs(including Alexa’s as well)
→ In the main mission you can choose between picking up the case file and picking up the tokens.