Giving at least a few more reasons as to why they thought the film was abominable would have been better than being saying it's so bad they can't talk about it.
The episode was bad. The Cartman plot felt uber-forced and it seemed like Trey and Matt were just going through the motions, wheras at least it seemded that Spielberg and Lucas were at least having a little fun making Indy IV, even if the final product ultimatly suck (and I personally didn't think Indy IV was THAT bad. Jeez, why don't they go after Friedburg and Seltzer, who are the ones that are truly ruining Hollywood).
Bottom line, that episode made me feel betrayed as a South Park fan the way Trey and Matt felt betrayed as IJ fans by Indy IV.
At least Spielberg demanded that the orginal version of ET be put on DVD along with the SE.
From
http://spscriptorium.com/Season6/E609secrets.htm
On a semi-related note, I'm a bit bothered by the fact that Trey and Matt have tons of money, and they don't even bother to give any to Lloyd Kaufman (President of Troma Entertainment and Creator of the Toxic Avenger), who distributed their first film "Cannibal! The Musical", according to Lloyd's interview with Matt and Trey on the "Make Your Own Damn Movie" DVD set.
Also, isn't it funny that Lloyd supports PETA, and yet Trey and Matt royally blasted PETA in an episode of South Park.
And if my logic seems odd, remember I have Aspergers Syndrome.