Any good pass D needs one of two things. A pass rush that helps the secondary or a secondary that give the pass rush an additional .5 second. The Cowboys have neither at this time. But a lot of teams don't have that, in fact, most.
Have you not seen receivers running loose through all of the secondary's so far? Wilson hit 5 different receivers for TDs, those no name receivers for NE were loose all day, Carr hit 11 different receivers and the Saints were running free through the Raiders secondary all night.
Just the games I have watched so far, it hasn't been hitting the open man, it's which man is the most open? And I don't think this is going to improve as the season progresses and more players are lost from the secondary's.