I didn't watch it either on principle. I get that people can be inspired by anything so that's not the issue for me. I don't do well with really, horrifically violent movies but that's me and I'm not generally offended so much as just grossed out. I just personally found that I didn't agree with the movie or the politics behind it, I certainly don't agree with Mel Gibson or have any wish to go to him for any sort of spiritual fuel or guidance at all.
I will say though that I was amused that people were generally OK with the level of graphic violence in "The Passion," to the point where kids (and I mean little kids) were being brought to the movie with Mom and Dad, but only a few years before that the people who largely filled the seats for "The Passion" were the ones who went ballistic over the graphic violence and torture in "Braveheart." Same director and like "The Passion" it was a historical drama of varying accuracy to real life that featured the real-life (with artistic liberties) struggle of a man regarded as a hero by a great number of people, but that torture scene was deemed disgusting and over-the-top.
I have a hard time seeing how graphic violence in "Hostel" is bad, or even in movies like "Eastern Promises" or "History of Violence" (both of which made waves for their graphic violence) where the violence was not only key to the plot, it is what forwarded the plot and the movie would have been lesser for it, the violence is condemned... But if Viggo Mortenson had been playing Jesus, it'd have been OK.
In the end though if he wants to make that kind of movie and people want to watch it, they can go right ahead. I'll opt out. I did for that Mayan disaster he did for the same reason. I've no need to see anything that over-the-top gross, I don't care what the director's reason for it is.