In this case it's corporate being especially protective of Batman, and terrified of anything that might affect toy sales (among other things). IIRC Justice League unlimited had quite a few episodes shot down or rewritten because of various Batman related edicts from on high. And parental backlash after Batman Returns is part of why we got Joel Schumacher. Hell, it's how we got Robin and the no killing rule, because they wanted to make the comics more marketable to kids.
Shit on the other side of the 4th wall is often the biggest problem superheroes face, and not just through censorship. It's why Spider-Man made a deal with the devil. And it's why Arkham has a revolving door, since popular and marketable villains need to keep coming back (which is why the "Batman should kill people" argument is idiotic, as any villain that won't stay in jail will also refuse to stay dead).
These are corporate owned characters. The company in charge is going to care far more about making money and protecting their brand than they will about art, consistency, or even whether their policies are rational. Hell, they canceled a Green Lantern show that was popular and successful because they weren't happy with the fucking toy sales.