Maybe Sacks aren't as a big a deal as I was thinking. I would be interested in Sacks for Q1 to Q3 versus Sacks in Q4. Heck, everyone who plays team defenses knows how much they love ends of games where your team is up a lot. I had Seattle for a good amount last year (or 2006) and I remember games against some bad teams with a big lead and just watching sacks add up (they had a good pass rush). I also saw a few INTs and even an INT for a TD in the last few minutes of games.
Most of the things on the "sins" list tie together. As far as why sacks are important, it is because they make an offense lose twice in one play: lost down
and lost yardage. Those are drive killers, and which help your own TOP & Field position. If a team is loading up on sacks early, it can help them get a lead.
If they get them late late, it means they aren't letting an opponent catch up, either way, it helps wins games.