Gargoyles, Young Justice, The Clone Wars, and the entirity of the DCAU for a start argue otherwise.
Oh sure, they can still be good, but it doesn't change the whole "cartoons are for kids" stigma being a hurdle. Some get around it, some strain against it, others... take the more extreme measure and over-compensate by packing their cartoon with "mature" content, to the point, ironically, of immaturity.
You can sort of see the seams of what I mean in that bible. For instance, the main character will get his hand on a "big old plasma cannon". And if I'm willing to guess, it will look nothing like a real gun
, it won't actually kill people, and the "real" guns that you would expect
won't show up much, if ever. Admittedly, Gargoyles was one of the better examples of how to handle these rules in a cartoon (Deadly Force and its long-term effects being the quintessential example), so I might also be wrong about that.
I guess what I'm getting at is that if they came out with a cartoon of Stargate, I'd wish they'd take a GI Joe: Resolute approach. Willing to kill, willing to use blood, willing to use actual guns
, but not trying to revel in the bloodshed or its mature content. Like live action Stargate.