There are any number of possible explanations for this trend, most probable simply being the increasing split between
blockbuster «entertainment» films that
dominate the technical categories while low -
budget (in) dependent films, driven by strong acting, directing and writing,
dominate the more prestigious awards, making a 7 Oscar win relatively rare (in order to reach that number, a film has to do well in either the effects or design categories, areas which favor big -
budget spectacle).