“People are suffering because their marriages are broken, not because they cannot go to Communion. For us, the center of the Eucharist is the consecration. Each Christian has the obligation to go to Mass, but not to go to Communion. To concentrate on only one aspect resolves nothing.”-- Cardinal Gerhard Müller
Prior to Vatican II when we had more than 90% of all Catholics attending Mass each Sunday, most Catholics did not receive Holy Communion when they celebrated Mass. There are a variety of reasons for this:
1. A well formed, keen conscience that prevented Catholics from going to Holy Communion when they felt they were in a state of mortal sin and had not been to Confession yet
2. The fast could not be maintained (when it was from midnight to the time of Mass and even when it was reduced to 3 hours before Mass or even the minimal one hour)
3. Irregular life situations such as divorce and remarriage that is an impediment
For a small minority of Catholics scrupulosity and an unhealthy sense of unworthiness prevented them from going to Holy Communion more often. For many it was the heresy of Jansenism. The Church requires by law that Catholics receive at least once a year by going to Confession first and this should be in the Easter Season.
After Vatican II rules were relaxed and the "new morality" led to unscrupulous lifestyles quite contrary to Catholic moral teaching. It all hinged not on external moral principles but on an internal awareness of right or wrong decided by the conscience even if this went against the moral law.
But more of an influence was the de-emphasis on the Mass being a sacrifice. It was touted as a meal and no one goes to a meal without eating. Everyone must eat and drink or the Mass made no sense. And if the Meal is all that is emphasized then it makes sense that everyone should eat when they go to dinner.
But the Mass is first and foremost the Sacrifice of Christ on the Cross in an bloodless way to make the graces of what brings forgiveness, redemption and eternal life to every person in the world.
So if a person doesn't receive Holy Communion they are receiving wonderful graces from the Sacrifice that is renewed in an unbloody way.
But let's be clear. There is only one person at Mass who must receive the Most Holy Body, Blood, Soul and Divinity of Christ and to complete the Holy Sacrfice and that is the priest who is celebrating the Mass.
It is here that modern theologians wanted to do away with what is critical for the completion of the Sacrifice because in their estimation it was clericalism not dogma. Folks, its dogma not clericalism to teach what is orthodox, that the priest-celebrant must complete the Sacrifice by consuming the Holocaust. This does not apply to anyone else simply attending Mass be it the pope, cardinal, bishop, priest of lay person.
It is noble and laudable for the laity to receive Holy Communion at every Mass if there are no impediments and many laity do for the benefit of their salvation, but it is not required!