As a, oh shall we say somewhat experienced filmmaker in this regard, I think much of the above makes for a delicious meal of red herring.
There are as many truly awful films that were tightly scripted, etc., and Lipsky's assertion that scripting is some path to betterment is folly.
There are also many truly awful films that were improvised.
So what might one learn from this? Maybe that it is not whether something is scripted or not, but whether all the aspects of a work - the underlying "idea" of it, the imagery, the sound, the acting (assuming there are acting figures, which itself is a fat assumption about what a film is - there's many stunningly wonderful abstract works with no actors) which all combine to make a film work or not. Maybe one should learn to open one's thought processes a bit, and think and feel a bit more clearly, and not jump to rather simple-minded views.
On a personal level I can pass along that of my own work, while each was rooted in some fundamental idea or structural framework, my films
CHAMELEON (1978); SLOW MOVES (1983); BELL DIAMOND (1985); REMBRANDT LAUGHING (1987); SURE FIRE (1989-90); ALL THE VERMEERS IN NEW YORK (1989-2000); UNO A TE (1995); all shot in film, were completely improvised - though frankly most people looking at them would assume they'd been fully scripted and thought out before hand, but they were not. VERMEERS had not one page of script or dialog,nor did any of the others listed above. What they did have, in the broadest sense of the term is "direction" and craft skills and an overarching cinematic sensibility guiding them.
Subsequently, the narrative digital films OUI NON (1996-2000), HOMECOMING (2004), OVER HERE (2006) and the most recent PARABLE (2008) were all similarly utterly without script.
It is true - sort of - that digital media, drastically bringing down the costs of actual shooting, enhances the opportunities to improvise and take risks. My shooting ratios are higher, though not by much, than they were in film (in film averaged about 2.5 to 1; though some films were virtually 1 to 1); I suspect now I average in narrative work something like 3.5 to one. I am not interested in wading through piles of crap to find a film in it. Some people are and some very good films have been made that way.
So the real matter is not whether one improvises or scripts, but rather how one goes about orchestrating the totality of what makes a film. Digital enhances this by letting people shoot, fall on their faces, make total crap AND LEARN IN PROCESS, rather than sitting around waiting for $2 million or whatever to materialize so they can go replicate a script and make another cookie-cutter film, however well or badly. And, for those few who seem to actually be willing to deal with it, digital also offers a far richer and more complex palette of aesthetic possibilities, though frankly most of our younger filmmakers treat it as if it was just cheaper film and don't begin to touch what it really is.
My two bits - a friend of mine in Stanberry MO, filmmaker Blake Eckard, pointed me to this item. Thanks Buck.