While it's generally a decent weapon in Titanfall, it was heavily nerfed in Apex and was considered one of the worst weapons in the game at launch - to the point that it became a meme. Despite getting improvenents throughout the game's lifetime, Respawn still leans into the memes by including Mozambique-related gameplay gags in Apex's April Fools events.
The name is presumably a reference to the Mozambique drill, a once-popular combat shooting technique so called because it was supposedly invented during that country's protracted war for independence in the 1960s and '70s. In the "classical" Mozambique drill, as favored by special forces in the 1980s, the shooter fires three shots at the target, endeavoring to place two rounds in the target's center of mass followed by one to the head.
