Why? Because he thinks the movie is a bit gratuitously violent? I haven't seen it yet, but there is enough critical mass out there to make that argument.
So what? That doesn't mean that Buckley is senile; it just means that he thinks Gibson was a bit loose with some of the account(much of which was based on the recounting of "visions" of a mystic, Catherine Emmerich). It appears that he was.
I'm forming the opinion that Gibson knew he had to make the movie violent in order to differentiate it from all the saccharin stuff that has gone before.
One should not automatically skewer someone who disagrees with the level of violence, since we cannot know just how violently Jesus was scourged.