Sometimes being physically violent is a thing that happens when emotions get boiling. It is unfortunate and it shouldn't happen, but it can and does.

That being said, nothing wrong with being uncomfortable with expressing a character doing so in your comic.

Ugh. Seriously? Morty's a weasel, but worrying about plagiarism at a time like this?

And it finally truly and sincerely hits Morty how -alone- he truly is. Before he was at least numb to this reality, however, he can't ignore it anymore, or how his "I stand alone" attitude has done nothing but left him isolated from everyone.

Demetrius on the other hand seem to realize that regardless of Morty's character, they need every scientist they can get. Or just doesn't want to see Ash acting like a thug regardless of who it's directed towards. Ash is acting like your typical fanfiction OC on this page, the character who verbally rips the unliked character a new one and makes clear who the 'real man' present is... and also deconstructs how immature such an attitude is.

Either Demetrius thinks Morty isn't worth it, or doesn't want to see Ash acting this, or just plain thinks fighting among themselves solves nothing.

Gona have to side with Mort on this one, mostly because this is not the time or place to vent your feelings or emotions, they are on a time limit with their friend life on the line and Ash is wasting it on quite honestly pointless bickering