In my opinion, the short answer is "Yes, but not as much."
Television is kind of relentless: it's the medium where if, at any point, your story flags a bit, your audience *will* change the channel. I've often thought that movies and even plays have an advantage here, in that once you're in the theater, there's a certain social stigma attached to walking out. (And besides, they've already got your money by then, anyway.) TV is the medium where moment-to-moment, you have to keep the audience interested.
Novels and even short stories allow a certain freedom, I think. They still have to be good, but there doesn't have to be this relentless adherence to keeping the audience engaged in "What happens next?" Moby Dick can wander off and talk about cetology for a chapter, and nobody minds.
This is not to say that prose writers disregard plot, and just spill out page after page describing the scenery. The good ones don't. So Mamet's principles -- ones largely designed to get the plot to behave -- do apply to prose fiction. But the stakes are lower. If you violate it, and your story's plot flags, it still might be beloved for other things.
You didn't piss off this prose-fiction-writer. I agree that you have a little more leeway in prose, but how much depends on the genre you're writing. Literary fiction and YA fiction are two different beasts and the audience for YA fiction is generally going to expect a faster-paced plot. It's going to be closer to television writing in that regard.
I think the reason plot isn't quite as all consuming in prose fiction is because voice picks up some of the slack. A lot of the slack, really. Many editors have said that they can work with a broken plot, but they can't do anything for a book without a voice. A good voice forgives a lot. If a reader is drawn to a voice, it makes exposition a little more bearable. On the other hand, it can't get too lengthy or readers will skip over it.
Completely, 100% agreed. Though I PREFER to have even my films and plays keep up the kind of dramatic action he describes, too. But you are right that there is a little more leeway. (I mean, "Waiting for Godot" as a TV show? Yeah, that'd get canceled before Gogo got his first boot off.)
Interesting for me to note, as usual, my 100% agreement with anything Mamet says about writing, and my 100% hair-pulling frustration with anything he says about acting or directing. It's the director's job to tell the actors to talk fast? Seriously? *facepalm* I've been curious about his new show "Race" on Broadway. And the #1 reason I haven't gone to see it yet is that he directed it. I just don't know if I can take it. Love his writing. HATE his directing.
Mmm..I don't know if I agree completely. I've read a few times that you need to be absolutely concerned about your reader's attention span and interest, because reading is a very active thing, and they can turn off and close the book very easily if you bore them. I try to finish books, and usually it's not a problem, but that's probably because the writer worked so hard to make the style and energy consistent throughout the whole book. I can easily see people putting a book down if the author goes off on a tangent for 2 chapters.
FWIW, I agree. Novels offer more room to play around in. All of any written work should move SOMEthing forward-- plot, theme, characters, or sometimes just tone-- but I think my hypothetical novel would suffer if, while I was writing it, I believed I couldn't take an indulgent detour from the main thrust when I was inspired to do so. Even if I couldn't find a way to integrate it with the main story, I'd probably retain my tangent because it was so fun to write and there's no hope of releasing a director's cut with special features and extras. But if it comes down to, will leaving this bit in keep it from getting published, then cut, cut, cut, of course.