I think this gets its right about the reviews of Jon Stewart’s turn as Oscar host:

There isn’t really much a host, whether it’s Dave Letterman, Whoopi Goldberg, Steve Martin, or the “gold standards” of hosts — Billy Crystal, Bob Hope, and Johnny Carson — can do to make the show any less of a bloated mess….

[T]hese critics forget one salient fact: this isn’t a fake news show, this is THE OSCARS, a show about entertainment and the movies. It’s not about politics or the media or race relations (to address the critics of Chris Rock). There’s only so much a host can do in that venue, especially a host that’s known for his edginess: if they make safe, funny entertainment-related jokes, they’re perceived as “tanking” (Stewart, Rock), but if they make edgy jokes that don’t land with the crowd in the theater, they’re also perceived as “tanking” (Letterman). It’s a no-win situation.