I feel like regarding the Snowdin incident, the robots in SteamWorks were probably programmed with standard morals and values, but they won't fully grasp what it means to take a life right? They're just taught that it's wrong, I imagine Axis not fully processing what happened and was more traumatised by how his body completely lost control to do something bad, along with Chujin's reaction most likely, but he still has that horrible feeling of guilt that he doesn't understand, he can't process anything so it gets blocked out because that's easier, if Axis learnt about what happened outside the context of vengeance route where he doesn't have a bigger thing going on to distract him, would he have just shut down?
I'm a heavy believer that Axis not being physically equipped to handle such complex and strong emotions, along with not having any support system as he isn't treated with respect and as a living thing with true emotions was what led to who he became today...