Cardinal Ratzinger suggests it as a sign of solidarity.

Q: Is not the proposal of a Eucharist fast [not to go to Communion], to which you seem to allude, contrary to the exhortations of many Pontiffs, beginning with Pius X?

Cardinal Ratzinger: No. I already made this proposal 15 or 20 years ago, the first time, in the context of the celebration of Good Friday, a day of fasting.

We find the roots of this fasting in the Gospel of Mark: “The days will come, when the bridegroom is taken away from them, and then they will fast.” And as early as the first century the Good Friday fast arose, expression of our “compassion” with Christ, who died on the cross for us.

The second time I spoke about this was when addressing the argument of divorced persons who have remarried, as today they are practically the only ones who cannot have access to Communion.

Each one of us should meditate on whether or not he should be associated, at least on some occasions, to this situation of exclusion. In this way, we offer them a sign of solidarity, and we will have one more opportunity to go deeper in our spiritual life.