I think there was a time where I might have agreed with you on that totally, I still see that they do have some talent. But I would pose that Sean Penn was just that good at surfer dude because he was surfer dude. He did steal the show. Madonna, I just found annoying, could barely suffer through the only movie I saw of hers, Desparately seeking Susan. Again, I would pose that she was that character. For instance, Tim Robbins, while a real die hard leftie, was quite chilling in some of his roles, equally mesmerizing in Antitrust as he was in Shawshank and Truth about Charlie. I don't care for his politics, but I do recognize his talent. Ridgemont High was just on the other day, Sean Penn was indeed really good in that.
I'll confess I never saw a Madonna movie. Her talents that I know are as a pop star and self-promoter. Further, I admit that Ridgemont High was the only Sahwn Penn movie I've seen. Obviously, I'm not much of a movie person! Primarily becuase they are mostly so lousy, it seems to me.
So I see you may be absolutely correct on Penn's Ridgemont High performance. I've just been assuming all these years he was talented, even though I never wanted to see the other movies he made because they looked to me like basically dumb ideas in the first place.