there is many movies where i dont understand why entertainment with those "themes" is being made at all ! i just saw
last house on the left ( http://www.imdb.com/title/tt0844708/ )
i felt pretty disgusted by it but it was through and through well made / acted and i loved the soundtrack (john murphy 
) so i couldn't give it a bad rating ... i knew nothing about the film before watching it. so i felt kind of ambushed by it. id prefer it if these kind of movies would not get made at all but they are which means there must be a target audience big enough to make this a financially worthwhile effort which than in turn makes me hate mankind again !
but than i am feeling if nobody made movies like saw hostel last house on the left the devils rejects etc than there would probably also not be a se7en or alien ...
and than i feel like a hypocrit ! ...
