“It’s easier to shoot uphill, than down. Plunging fire also has more limited effect than raking fires.”
Now, there’s a unique perspective. Were you in the military? Have you not read Sun Tsu’s “The Art of War”?
“All armies prefer high ground to low and sunny places to dark.”
“Do not climb heights in order to fight. So much for mountain warfare.”
It’s another tactical justification for reverse slope defenses.
Placing an observation post on a hilltop provides max visibility for the observers defending the area. Unfortunately, the observers also become targets for all known enemy in the area. So when an enemy attacks, they are likely to attack those positions with indirect fire first.
Reverse slope defenses are used to help mask friendly positions from enemy observation prior to their commitment to an assault. They also afford the defenders fighting and alternate positions not previously observed by the enemy, giving some element of surprise when they defend. The defenders are also shooting uphill into the enemy, making it easier to produce grazing fire and easier to aim the rifle upon recoil. More accurate rounds downrange in less time than fewer inaccurate rounds in more time.
I believe the Israelis used the tactic in the ‘74 war and in the Golan Heights. First UN observers on the scene afterwards were puzzled by the tactic, but it makes sense.