There's going to be a lot of lamenting the soft zone this year but as Largent points out, the die was cast when we went into the season with the corners we have. We are definitely better than last year's zero pass rush on the DL, but we'd have to have a monster pass rush to protect those corners and that's not what we have. We have Dunlap and some guys with potential who may or may not make any great leaps, and are more likely to be inconsistent.
When asking why a coach would ever use a soft zone that gives up easy yards over the middle, the question is "what's the alternative." Fans tend to believe that aggression is a better approach. Press-man, man to man, blitz heavy if the front 4 aren't getting home. There are times when you need to stop a drive to save the game, like we did in OT, and as Dib said, we tightened it up and got off the field. But when you have a lead, and your corners are Flowers and Reed, first and foremost you're thinking about not giving up the big play. Getting hit over the middle sucks and is frustrating, but at least it takes the opponents a half to catch up to you (if your offense isn't doing squat). Put Flowers on an island in man coverage or force him to play at the LOS and get instantly smoked, and your lead vanishes much more quickly. As Dib points out, the soft zone sucked, but giving up the big play to Henry on a too-aggressive angle was the real dagger.
The head-scratcher is, why play soft-zone which is a delaying tactic kind of approach but then not play ball-control offense? The combination of the two is what left the D out there all game and all but ensures they will wear down against a physical offense.
Which is why I feel that, pathetic as it was, the defensive strategy was the best of the bad options with the corners we have, while the offensive strategy was off and offense has better personnel. No reason we couldn't have run the ball more or go for some nice short and intermediate gains to TEs or whatever in the second half.