The NBA is a copycat league. If a team mixes things up and finds a new way to win, you'll see other teams soon follow suit. The Showtime Lakers of the 1980's got more teams using the fast break. The Bad Boy Pistons had an effect on Pat Riley's Knicks and Heat as toughness became paramount.
When the Suns almost made it to the NBA Finals under Mike D'Antoni and led by Steve Nash, the pace of the NBA sped up again and 3-point attempts took a larger leap. Then when Steph Curry's Warriors starting winning championships, every team's pace and 3-point attempts exploded which brings us to today where half a team's shots are 3's.