No bro , you are just used to the moder rpg garbage. [...] you dont have to use your brain basically.
Are you calling NWN1 'modern rpg garbage'?
And apologies, but that is just bad game design. You should not be able to ruin your game with no way of recovery or some sort of *immediate* warning/hint (for allowing a reload to fix the mistake).
"You have killed Malady. You hear the pounding of heavy boots as a host of enraged magisters is bearing down on you. The last thought that crosses your mind as you sputter blood is that that might not have been the best idea you ever had. GAME OVER."
"You have destroyed the book that could have told you where to find X. For a while, you desperately try to find clues, but your search remains fruitless. You spend your last years reminiscing about your adventuring days and wishing you had not set fire to those precious pages. GAME OVER."
Allowing the player to sink 20+ more hours into the game after the fateful moment only to then discover that they ruined their entire game would just be sadistic, if done on purpose.