Front tapers help disperse energy to the leader and fly from the belly. If the front taper is short (under 3 ft) and you don't have a longer leader (11-13ft) there can be too much energy left in the system and the fly could kick to the side at the end of a cast losing accuracy and distance.
If the front taper is long (3-8ft), more energy is dispersed over that longer taper leaving less energy left in the system by the time it gets to the leader. This could reduce the odds of getting your leader to lay out straight with no slack on your presentation. This is HUGE in salt water fishing.
It is important to have a good balanced leader system that acts as a continuation of the front taper of the fly line. This will help transfer energy smoothly all the way to the fly. This is vital for a successful salt water presentation and catching fish in the salt is all about the presentation.