Adaptation was an interesting movie, and I enjoyed it thoroughly. Perhaps one of my favourite things about the movie was the use of irony to make a point. I found the movie interesting enough before It suddenly became and action movie.
At the beginning of the movie, Charles has a rant about how he doesn't want to go mainstream and make cliché romance or action scenes. Yet when he gives in and goes to the seminar, he changes his mind and the movie gets more action-based, with romance, and much more corny. I personally, did not like the movie after the seminar, because it became brain-numbing and cliché. But I think that's the point. The movie became less appealing because he followed the seminar instructor's advice and the movie no longer became good, or original. It was obvious and two-dimensional.
I think the point to be made with Adaption is that the life of a writer isn't easy. There are easy ways out by following rules, but that doesn't make a good movie. When writing, it is important to go with what you feel is write, and write about what you care about, instead of jazzing up a story with what you believe the audience will like, such as romance and action.
I, personally, have seen too many cookie-cutter movie plots with two-dimensional characters. Sometimes I feel there was more effort in graphical effects than a proper script, and it bothers me. I agree with Charles, that if you remain true to yourself as a writer and focus on the things that you believe to be important, such as character and plot, then you will have a fine script.