The Court does not have to tell us why they eschewed to look at a case. The Justices look at hundreds of cases each term. I sort of remember they sit around and discuss what's in front of them. Don't recall if they vote while in the presence of the others, or whether they decide in private. The Court seems to always shy away from Second Amendment cases. It's the briefest of all in the number of its words, yet the Court seems to run from it whenever a case arises involving it. Maybe things will change when Trump puts a new Justice (one or even two) on the Court to replace Breyer and Ginsberg. T'will be a great day in American history when those two (can't use the words I really want to use) are no longer violating our Individual Liberties as American citizens.