My sense is that DCs or defensive-oriented HCs value ST more than OCs or offensive-oriented HCs. First of all, do others agree with this? Second, if it is true, why is this? Good punt/kickoff units go hand-in-hand with a defense, potentially giving opposing offenses longer fields. So I can see DCs valuing ST. But good return units can potentially give offenses shorter fields, so OCs should value ST as well. Somehow that doesn't seem to be the case, though.
Now, here's something that I don't quite understand: My sense is that DCs like and value the FGs in a way that an OC may not. My best guess at why this is: DCs want conservative outcomes from their offense--namely, ball security and consuming the clock (usually via running the ball). But what about points? That's where the kicking game comes into play. If the conservative offense can't score a lot of points, that's OK because ST will make up for that--via FGs and returns. DCs don't want turnovers because this makes it tough for their defense.
Most OCs or offensive-oriented HCs are not going for this. They want their offenses to be great at scoring points, and if that means a little more turnovers, so be it. (Well, at least some OCs may feel this way.) Additionally, while OCs may want to devote considerable resources to the defense, because they understand the value of a good defense, they may not be reluctant to sacrifice resources to ST. Perhaps, they're less concerned if their offense has longer fields--because their offense will be good at moving the ball and scoring....This doesn't sound right, but that's the best I've got so far.
(On a side note, while writing this, I thought of the sideline fight between Kevin Gilbride, a run-and-shoot OC, and Buddy Ryan.)