While it may feel like the 2015 NBA Finals have made it rain 3's, the truth of the matter is that the percentage of 3-pointers shot is at a 5-year low of 33.1%. You'd have to go back to 2010's Lakers-Celtics Finals to see a worse performance (29.3%).
So why does it feel like there are so many long balls in this year's finals? Because there are... they just aren't landing in the bucket.
On average there are 59 3-point attempts per game in the 2015 NBA Finals, more than any year dating back to 1990.