They wanted to have a chase scene with dune buggies running around the desert and Michael Dorn firing a pintel mounted phaser cannon of some sort off the back.
They wanted to show the new Enterprise crash into something.
They wanted to kill off Brent Spiner's character but leave an out in case they actually did another movie and he wanted to be in it.
They stuck those three elements together around a really weak plot.
I'll stop going to movies for awhile.