I agree, the one funny joke was Uncle Matt's postcard, lol. Other than that it was just obvious they weren't that familiar with the show.
I still think it should have ended with Wembley saying... "uh... how do
we do it again?" Still, it's basically an unfamiliarity with any character besides Doc and Uncle Matt that ruined the sketch. I know what it was going for, though I don't know if it was slightly more accurate to Watership Down than Fraggles.
But that's the crapshoot with Robot Chicken. You either get a wonderfully, dementedly brilliant sketch like Captain Planet (look it up it's officially posted).... I mean, that was just wonderfully done.
Or you get 1980's cartoon character doing drugs/drinking/sex/ lame cheap jokes like that.
With Mad, you get consistency... it's been solidly getting better in its second season with better animation. Plus, when it parodies something, it goes for parodying the
substance. There's a whole lot of sketches I could recommend... Gordon Ramsy's Kitchen Nightmare before Christmas (done in stop motion), The Cowboys and Aliens parody... Money Ball Z...