Why Spidey doesn't crack jokes in the movie:
It would get too annoying and his jokes would be too lame.
Him showing humor at a dangerous time would show a very immaturity side and his inability to take something like a big fight or someone's life a stake seriously.
Imagine;
Venom: I've got Mary-Jane and I'm going to throw her off this building!
Spidey: *Lame-ass joke*
Venom: Wow. Way to take the situation seriously...
Makes sense. Nearly all the times he's confronted a villain in the movies has been a very serious time, so it's not like he's going to crack some stupid joke.