Interesting discussion this am on NFL radio - it wasn't about the Rams, but got me thinking. Charlie Weiss was saying if your defense is a liability - why put them on the field first and possibly start the game down by points. He and Bob Papa were essentially saying there's no guarantee that you'll have the ball at the end of the half and first half possessions can vary a lot in terms of timing.
For the Rams - I don't have the stats but it seemed like we generally defer the opening kickoff and more than once - teams marched down the field on us and scored. It seemed as though we started a bunch of games in the hole. Our defense was chronically underperforming on opening drives.
You see how we did nothing with the 2nd half kickoff in Detroit. If that was due to us deferring - it didn't work.