Part of that reaction is also due to the existence of Serenity
Most of what got people riled about the cancellation was that incredible sense of unfulfilled potential. Given that, we all watched the show about a dozen times in order to pull out every nuance.
But with the movie being a part of the viewing experience now.....it actually has an ending. Maybe not a complete ending, but something. I think that tends to dull the fanaticism of new viewers, just as it's calmed those of us who were there from the start.