The core concept of humor is that it's at the expense of someone or something. For Retsupurae, it's a subpar product. Whether they take issue with the Let's Player, the game on display, or whatever, the intent is to just crack some wise at a product that failed to exhibit a game without any distractions (or the game itself isn't worth taking seriously, as seen in their "wrongpuraes"). As a humor channel, quite frankly, this social justice stuff isn't their job, so why treat them as if it is?
Social justice is everyone’s job (if you’re a decent human being), and there’s no time off I’m afraid. Sorry, but sexist and transphobic jokes are NEVER ok.