At first there were 70 stars because Bowser demanded it. Then there were 16 stars because MIPS the rabbit demanded it. Then there was 1 star because Bowser's Sub demanded it. Now there are none because the viewers are impatient and demanded the game be quicker.
As with many other runs on this site, the goal of pure speed has resulted in the complete breaking of the game. Very little of the game's normal play remains. If you'd like to see more of what Super Mario 64 offers, see the 120 stars run.
This movie is an 8 second improvement to the previous movie due to a "series of improvements" discovered by the author, detailed in the submission message.