Jon Stewart doesn’t challenge gun ownership per se, but rather the sh%$ storm freakout accompanying Bob Costas’ comments on gun violence in the context of the Jovan Belcher murder/suicide.
He made the rather unremarkable observation that absent Belcher’s (legally owned) firearms, he and Kasandra Perkins might still be alive today.
The NRA, and its inadequately endowed paranoid ilk, want to make discussions of gun violence, and gun culture literally unspeakable in the media.