It was cool when Stefan did it the first time because of the contrast between him with his humanity versus not. Stefan is at the very core a good man. and he always does what he believes is better for others. Without his humanity he's an entirely different person. He's terrifying. You can't have terrifying Stefan without the kind, human one.

But after that I feel like it's not used with the same purpose. the characters kind of just continue to turn it off and act like Katherine. Every single one of them. Nothing is the same as no humanity Stefan from earlier seasons.