I think Roger is being very smart and showing great foresight in not playing in DC. I believe the primary reason, in Roger's mind, for not investing his efforts in DC is the unavoidable rationale that the Swiss cannot win at the moment, even with him on the team. Even if Roger delivers on both of his rubbers (as he almost unboubtedly can and will), the possibility of a 2-3 defeat will always loom large, especially if they are playing a perennial contender. I think everybody will more or less agree that Stan, Marco and Co., although very good players, cannot guarantee one of the other two singles rubbers and the doubles rubber (even with Roger playing) becomes very uncertain if they face a country with a doubles specialist team (e.g. the US).
I think Roger is being very pragmatic. It would be unwise of him to invest his time, energy and effort in DC just to lose 2-3 in the semis or even the final. I believe he is waiting for the setup around him to strengthen so that the team can give a fair go (he even mentioned something about this a few times). Note that he gives it his all to keep the Swiss in the World Group - he even played in the doubles rubber last year!
Additionally, I believe Roger knows that the Swiss fans and federation understand this. No one will deny that the Swiss are patriotic. But, I admire the fact that they are never "in your face" with it (sort of like us Canadians
). They will respect Roger's decision in the spirit that it is made. They know that there will come a time when he will give it his all to win the Cup and they know that circumstances are not quite there yet.