It's not just fire suppression. We've got a trifecta of drought, bark beetle infestation and fire suppression (aka, tree density).[0] It's the killer combo.
This needs more upvotes. I agree that our fire management hasn't been great, but there is more to it than that. Climate change is driving both more fuel and deeper droughts, and making better conditions for bark beetles. There isn't a single answer to this.
Still, fire suppression is the 800 pound gorilla. We're not just seeing fires in the conifer-dominated Sierra. It's also in the savannah and scrub zones as well. These all burned regular in prehistoric times.