They want to push the envelope so far that their viewers aren’t even sure if they’ll continue watching. Then there are those directors who don’t care about that agreement. There may be some laughs, some jolts, and possibly a tear or two, but nothing that will leave any permanent scars.
There’s an unspoken agreement between moviegoers and filmmakers who make safe, mainstream fare: if the former gives the latter’s work a look, the latter won’t do anything to disrupt the viewer’s emotions beyond what’s usually called for.