Strong pass rush does wonders. Without it, someone will ALWAYS get open if the QB has all the time he wants. It's just the nature of the game and no DB on the planet can cover that long. Effectiveness dominoes from the front backwards on D.
And, yes, obviously the DBs had awful habits last year and I do blame Howell. I see no other way in which multiple DBs got worse from one year to the next. They had bad habits, they'd bite on everything, they wouldn't turn and look, they couldn't tackle, etc. There's no way those guys are going to learn from a guy who isn't respected and isn't the greatest leader.
Can't ignore either one. Point is, some of those errors had absolutely nothing to do with the pass rush. They were just bad habits by the DBs.