I'd venture to say... [eeeeeeep: spoiler alert I almost failed to note!!!!]
...that most "serious dramatists" have never read The Poetics. And further: art in the 20th and 21st century has been all about expanding beyond boundaries that prior eras imposed upon themselves.
Tom is just pissed that Joss offed Wash. And Tom did not enjoy the feeling that there were more offings in the offing. And for Tom, it is not enough just to express an opinion. Instead he has to show how his opponent has committed some crime against humanity.