Bill Burr is ripping folks who think Los Angeles botched the wildfire situation ... he says critics have no clue what they're talking about.

The comedian took a bunch of shots at the online commentary surrounding L.A.'s response to the devastating infernos during an appearance on "Jimmy Kimmel Live" Tuesday night ... characterizing the criticism as folks sitting around in their underwear posting nonsense.

Bill pours water on a couple popular talking points among critics on social media ... bashing the idea that illegal immigrants and homeless people are the scapegoats here. He says people living on the streets light fires every day to survive and doesn't buy the theory they somehow sparked the blazes in Altadena and the Pacific Palisades.

Bill's also ripping armchair quarterbacks who are wondering why L.A. wasn't able to get water on the fires right away ... he says the extremely high winds made it impossible for helicopters and planes to drop water on the blazes the first night.

The overall feeling online is that this whole situation was mismanaged ... and Bill's giving those folks a piece of his mind too.

He says people should focus their rage on insurance companies instead -- because thousands of homeowners were dropped by their insurers recently ... ending his rant with a reference to Luigi Mangione.

Bill lives in L.A. and says a change in the wind spared his home from the flames ... though he still had to evacuate with his family.