Well, close. It is true, in the way that baseball can be boiled down to "hitting a ball with a stick and running around in a circle".
More to the point, I think I've heard of D&D monsters referred to as "bags", "pinatas", and "containers" of "XP and loot" roughly once for every monster I've killed in a D&D campaign. And I've done Dragon Mountain twice.
That's why it's not funny. Because it's tired.