Why? Why should this person have said something about both sides?

Because failing to acknowledge the major differing and valid viewpoints in a complex situation contributes to echo chambers and radicalization which can ultimately lead to or contribute to political disfunction, civil war, war and deaths.

Because of the several layers of indirections I think it’s completely unreasonable to expect people to live up to the expectation of acknowledging differing valid viewpoints, but people who fail to do so are still engaging in shitbaggery, in my opinion, because they contribute to the deterioration of the political discourse which can have catastrophic consequences.

As I said I generally think that engaging in shitbaggery in political discourse shouldn’t harm your job /career. Unless your job relies heavily on your reputation, which lawfirms seem to weirdly believe is the case for lawyers. I personally don’t get it, a lawyer’s argument should always be just as a valid regardless of which lawyer makes the argument, but I know very little about law practice.