Speaking of Alfred Hitchcock, I've always liked this one, attributed to the Master:
"Drama is life with the dull bits cut out."
And, for a more recent, pithy analysis of ever-lengthening movies and life, here's Denis Leary's take on film, (take that Peter Jackson, again):
"What I've learned is that life is too short and movies are too long."
I'm very fond of the often condescending comments about Hollywood emitted by writers, (these bon mots usually seem to drop from over their shoulders as they leap into their Bentleys or Jags to drive to the bank to cash those checks from the studio boys):
"Having your book turned into a movie is like seeing your oxen turned into bouillon cubes." ~John LeCarre
"Hollywood is a place where a man can get stabbed in the back while climbing a ladder."~William Faulkner
"Great beauties are infrequently great actresses, simply because they do not need to be."~Garson Kanin (on Hollywood movie stars)
"There were times, when I drove along the Sunset Strip and looked at those buildings or when I watched the fashionable film colony arriving at some première … that I fully expected God in his wrath to obliterate the whole shebang." ~S.J. Perelman
On being told that his storytelling was "old hat", in 1976: "They say Wilder is out of touch with his times. Frankly I regard it as a compliment. Who the hell wants to be in touch with these times?"~Billy Wilder
"I think it can be said fairly that I've been in on the beginning, rise, peak, collapse, and end of the talking picture."~Joseph L. Mankiewicz
(On live television at the premiere of Cleopatra (1963) after being asked how he felt now that the movie was finally in the can and about to have its first showing] "I feel like the guillotine is about to drop."~Joseph L. Mankiewicz
[At the same occasion, at the opening of Cleopatra (1963) when host Bert Parks called the film "a wonderful, wonderful achievement"] "You must know something I don't."~Joseph L. Mankiewicz
"I am never quite sure whether I am one of the cinema's elder statesman, or just the oldest whore on the beat."~Joseph L. Mankiewicz
I think it's fair to say that Mr. Mankiewicz was a tad disenchanted, eh?