Yes, he was simply attempting to promote his film, it seems.  But he was asked to define certain things he feels is a sin ...sort of depicting it like the huge scarlet letter 'A' that Hester Prynne had to wear, in Nathaniel Hawthorne's novel.  Kirk didn't repeat the word 'sin', but opted to call it unhealthy, or something like that.  Sin is actually separation from God ...separating from what He tells us in the Bible, and I'd say that sort of separation is unhealthy.  Sin is also a process ...moving away gradually from God, perhaps not knowing we are doing it because we have rationalized it so often ...we no longer are sensitive to His directing us.  It's also sin to demand the removal of a manger scene from a building ...which so long had merely followed a simple act of decorating  according to tradition ...Christmas being a celebration of Christ's birth, so why can't we depict just that, Christ's birth.