He just showing off really. There is no need to split shift unless you have a really heavy load.
I have been driving deuces since the early 70's....splitting gives you two extra gears loaded or empty...you will acceleate faster
by splitting and cause less wear and tear on the driveline.
Splitting is an aquired skill and should be practiced when empty and used all the time when loaded or while driving slowly in
a motor pool type envionment.
I was a drivers trainer/instructor/license examiner when I was in the Active Army....any soldier that could not split shift to my
standards did not get a license.
In most Motor Pools I was at it was required to put tactical vehicles in Low Range upon entering the gate and to have a Ground
Guide walking in front of the vehicle until it was parked.
Splitting gears is not (IMHO) showing off.