turning off a 'humanity' switch does not justify immorality
For:
If one may choose to turn off their moral compass and is capable of mass murder with impunity, then it would an incredibly immoral act to turn off that switch.
If the 'switch' is not turned off by choice, then their very existance is predatorial, and they are completely deluded in thinking they can be 'human' in the first place. At the end of the day, this show will say anything to try and justify murderers shacking up with 17 year old girls.
Its not a flaw with the whole show, but the writers try the humanity switch line way too often as a cheap justification for crimes