Why don't we get turnovers, and why do we fumble so much?

We have a quarterback who is smart with the football. He avoids the rush, gets rid of the ball fast, and doesn't throw many interceptions. However on defense, it seems like we very rarely get interceptions especially from our secondary. And our secondary seems to get schooled alot like they are the sparring partner for NFL offenses. We don't seem to get all that many forced fumbles either. On offense, our RBs and WRs tend to get stripped by defenses that make an active attempt to get turnovers.

Why aren't the coaches preparing our guys better in the turnover department? I know we don't have much speed at LB or much talent/speed in the secondary, but it seems we could at least do better.

It seems like Drew has to try to outscore the other teams high powered offense every week, and if he has a bad game or if our skilled players fumble, we have very little shot to win.