There is no more important concept on the front burner of basketball minds than efficiency. The rise of "Mathketball" -- basketball strategy driven by analytics -- has influenced the way the best teams execute both offense and defense, as teams seek to capitalize on scoring opportunities by attempting shots in high efficiency areas while simultaneously limiting those of their opponents.
The main scoring areas in the half court are commonly broken down into three categories: rim field goal attempts, midrange and 3-point attempts (which can be further broken down into corner versus above the break 3-pointers). The most efficient shots are layups and dunks at the rim, followed by 3-pointers, so it stands to reason that the most efficient style of offense would emphasize shots in these spaces and try to minimize the number of shots in the midrange.
The idea is that the rate of success for making rim field goal attempts is much higher than making jump shots, and if you are going to take a jump shot, you might as well take a few steps back and be awarded an extra point for the added risk. The "long 2-point attempt (from farther than 16 feet) is the worst shot in basketball" nomenclature is derived from this concept, that the shooter is assuming more risk for less reward.