Punish married couples for the sins of the DC council?
That said, I think the archbishop's decision to deny spousal benefits to certain persons married in the eyes of the Church is a mistake, both as a principled matter and as a practical one.
First, the archbishop's fears about his coming across as legitimizing "same-sex marriage" unless he cuts off spousal benefits seem misplaced: no action performed under compulsion can be construed as necessarily signaling approval or agreement with such action. This is basic moral reasoning, and without it, consciences are subject to infinite scruples and society quickly ceases to function.
Second -- and even though, like most good lawyers, I don't go around looking for battles nor do I lightly recommend them to others -- what appears to be a very promising case to fight this intrusive legislation is being squandered by the archdiocese's capitulation to the policy. The archdiocese seems to have very good facts on its side and is blessed with real resources to fight this civil imposition on its governance. It could doubtless attract significant support from others if it turns and fights. If it folds, however, not only is its own position lost, but many other smaller operations, less able to resist, will doubtless come under added pressure to conform.
Third, as it stands, the archdiocese's decision does not deny a single gay-couple coverage, but it does deprive people who are trying to live in accord with Church teaching on marriage and the family the dignity of having their vocation recognized in something besides papal encyclicals and catechisms. The pressures bearing down on married couples, especially those raising children, are burgeoning, while the concrete gestures of support toward them are becoming ever fewer and further apart. One of these days . . .
There are, I think, other problems with Abp. Wuerl's decision to eliminate certain spousal benefits rather than to risk paying them to same-sex couples, but the foregoing should be enough to suggest that the current approach has serious deficiencies.